13-Letter Words Starting with I

All 261 thirteen-letter words that start with I

IC

• ichthyologist25n. An expert in ichthyology: one who studies fishes.
• ichthyosaurus24n. Any members of the genus Ichthyosaurus.

ID

• ideologically20adv. In an ideological manner; with respect to ideology.
• idiomatically21adv. In an idiomatic manner.
• idiosyncratic21adj. Peculiar to a specific individual; eccentric.

IG

• ignominiously19adv. In a manner which is ignominious (“especially of a person: deserving of...

IL

• illocutionary18adj. Of, pertaining to, or deriving from illocution, the performance of acts...
• illusionistic15adj. Tending to create an illusion.

IM

• imaginatively22adv. In an imaginative manner; showing creativity.
• immateriality20n. The state of being immaterial.
• immunobiology23n. The branch of biology that deals with the biological effects of the...
• immunological20adj. Of or relating to immunology.
• immunosorbent19n. An antibody that is used to remove a specific antigen from a mixture.
• immunotherapy25n. The treatment of disease (especially cancers and autoimmune diseases)...
• impeccability26n. The property of being impeccable.
• imperceptible23adj. Not perceptible, not detectable, too small in magnitude to be observed.
• imperceptibly26adv. Not noticeably; such that it cannot be detected, through being too...
• imperialistic19adj. Of or pertaining to imperialism or imperialists; favoring imperialism.
• imperiousness17n. The quality of being imperious.
• impermissible21adj. Not permissible; not to be permitted or allowed.
• impermissibly24adv. In a way or to an extent that is not permissible.
• impersonality20n. The state or quality of being impersonal.
• impersonation17n. The act of impersonating.
• impertinently20adv. In an impertinent manner.
• imperturbable21adj. Not capable of being, or not easily, perturbed, excited, or upset; calm...
• imperturbably24adv. In an imperturbable manner; calmly.
• impetuousness17n. The state or quality of being impetuous; making arbitrary decisions.
• implacability24n. The quality or state of being implacable.
• implementable21adj. Able to be implemented.
• importunately20adv. In an importunate manner; with persistent or urgent solicitation.
• impossibility22n. Something that is impossible.
• impoverishing24adj. Tending to impoverish (To weaken in quality; to deprive of some...
• impracticable23adj. Not practicable; impossible or difficult in practice.
• impractically24adv. In an impractical manner.
• impressionism19n. An art movement characterized by visible brushstrokes, ordinary subject...
• impressionist17n. One who adheres to the theory or method of impressionism.
• improbability24n. The quality or state of being improbable; unlikelihood.
• improvidently24adv. In an improvident manner.
• improvisation20n. The act or art of composing and making music, poetry, and the like...
• improvisatory23adj. Of, pertaining to, or in the nature of improvisation.
• impulsiveness20n. The quality of being impulsive.

IN

• inadvertently20adv. Unintentionally; because of an oversight.
• inappropriate19adj. Not appropriate; not suitable for the situation, time, or place.
• inattentional13adj. Related to, or caused by inattention.
• incandescence20n. The emission of visible light by a hot body.
• incapacitated20adj. Rendered unable to act; restricted from taking action.
• incarceration17n. The act of confining, or the state of being confined; imprisonment.
• incarnational15adj. Pertaining to incarnation, particularly the incarnation of Jesus Christ.
• inclusiveness18n. The property of being inclusive; inclusivity.
• incombustible21adj. Not capable of catching fire and burning; not flammable.
• incommunicado22adj. In a state or condition of inability or unwillingness to communicate.
• incompetently22adv. In an incompetent manner.
• inconceivable22adj. Unable to be conceived or imagined; unbelievable.
• inconceivably25adv. In an inconceivable manner, in a way not believable or understandable.
• incongruously19adv. In an incongruous manner.
• inconsiderate16adj. Not considerate of others.
• inconsistency20n. The state of being inconsistent.
• inconspicuous19adj. Invisible.
• incontestable17adj. Not contestable; indisputable; certain.
• incontestably20adv. In an incontestable manner.
• incontinently18adv. In an incontinent manner; without restraint, or without due restraint.
• inconvenience20n. The quality of being inconvenient.
• inconvertible20adj. Not convertible.
• incorporation17n. The act of incorporating, or the state of being incorporated.
• incorrectness17n. The characteristic of being incorrect.
• incorruptible19adj. Incapable of being bribed or morally corrupted; inflexibly just and...
• incredibility21n. The quality of being incredible; incredibleness.
• incredulously19adv. In an incredulous manner; tending to disbelieve; skeptically.
• incrementally20adv. In an incremental fashion; by small changes.
• incriminating18adj. Causing, showing, or proving that one is guilty of wrongdoing.
• incrimination17n. The act of incriminating someone.
• incriminatory20adj. That incriminates.
• inculturation15n. The adaptation of Christian teachings in a non-Christian culture.
• indefatigable20adj. Extremely persistent and untiring.
• indefatigably23adv. In an extremely persistent and untiring manner; in an indefatigable...
• independently20adv. In an independent manner.
• indescribable20adj. Impossible (or very difficult) to describe.
• indescribably23adv. In an indescribable manner.
• indeterminacy21n. The condition of being indeterminate.
• indeterminate16adj. Not accurately determined or determinable.
• indeterminism18n. The doctrine that all human actions are not so much determined by the...
• indifferently23adv. Tolerably; passably.
• indiscernible18adj. Not capable of being discerned or perceived.
• indispensable18adj. Absolutely necessary or requisite; that one cannot do without.
• indispensably21adv. In an indispensable manner; such that one cannot do without it.
• indisposition16n. A mild illness, the state of being indisposed.
• individualism20n. The tendency for a person to act without reference to others...
• individualist18n. Someone who believes in individualism as a sociopolitical system.
• individuality21n. The characteristics that contribute to the differentiation or...
• individualize27v. To give something its own individuality; to characterize or...
• individuation18n. The process of individuating or individualizing.
• industrialism16n. The socioeconomic system based upon the industrial production of...
• industrialist14n. A person involved in the ownership or management of an industrial...
• industrialize23v. To develop industry; to become industrial.
• industriously17adv. In an industrious manner.
• ineffectively27adv. In an ineffective manner; not producing any significant or desired...
• ineffectually24adv. In an ineffectual manner.
• inefficiently24adv. In an inefficient manner.
• inegalitarian14adj. Characterized by inequality between people.
• ineligibility19n. The state or quality of being ineligible.
• inevitability21n. The condition of being inevitable.
• inexhaustible25adj. Impossible to exhaust; unlimited.
• inexhaustibly28adv. In an inexhaustible manner.
• inexpensively28adv. In an inexpensive manner.
• inexperienced25adj. Not experienced; lacking knowledge because lacking experience.
• inexpressible24adj. Unable to be expressed; not able to be put into words.
• inexpressibly27adv. In an inexpressible manner.
• infallibility21n. The property of being infallible; the ability to never make a mistake.
• infeasibility21n. The state of being infeasible or impractical.
• inferentially19adv. With respect to, or by means of, inference.
• infinitesimal18adj. Incalculably, exceedingly, or immeasurably minute; vanishingly small.
• inflexibility28n. The quality or state of being inflexible, or not capable of being bent...
• inflorescence20n. A group or cluster of flowers arranged on a stem that is composed of a...
• influentially19adv. In an influential manner.
• informational18adj. Designed to or able to impart information; possessing information.
• informatively24adv. In an informative manner.
• infraspecific25adj. Pertaining to a taxon at a rank lower than species, such as subspecies...
• infraspinatus18n. A thick triangular muscle whose main function is to rotate the arm...
• infratemporal20adj. Below the temple or temporal bone.
• infuriatingly20adv. In an infuriating manner.
• ingenuousness14n. The condition of being ingenuous.
• inhomogeneity22n. The state of being inhomogeneous.
• inhomogeneous19adj. Not homogeneous.
• inhospitality21n. Lack of hospitality.
• inoffensively25adv. In an inoffensive manner.
• inopportunely20adv. In an inopportune manner.
• inorganically19adv. In an inorganic manner.
• inquisitional22adj. Of or pertaining to an inquisition.
• inquisitively28adv. In an inquisitive manner; curiously.
• inquisitorial22adj. Of or pertaining to an inquisition, specifically the Inquisition.
• insatiability18n. The condition of being insatiable.
• inscriptional17adj. Of or pertaining to inscription.
• insectivorous18adj. Feeding on insects.
• insensibility18n. The property of being insensible.
• insensitively19adv. In an insensitive manner.
• insensitivity19n. The condition of being insensitive.
• insidiousness14n. A surreptitious harmfulness, quality of entrapment, or treacherousness...
• insignificant19adj. Not significant; not important, inconsequential, or having no...
• inspirational15adj. Having the ability to inspire.
• instantaneous13adj. Occurring, arising, or functioning without any delay; happening within...
• instantiation13n. The production of an instance, example, or specific application of a...
• instinctively21adv. Innately; by instinct; without being taught.
• instinctually18adv. In an instinctual way.
• institutional13adj. Of, pertaining to, characteristic of, or organized along the lines of...
• instructional15adj. Intended for purposes of instruction, for teaching.
• instructively21adv. In an instructive manner.
• instrumentals15n. The backing track of a song. The audio of a song without the vocal...
• insubordinate16adj. Rebellious or defiant to authority; contumacious.
• insubstantial15adj. Lacking substance; not real or strong.
• insufficiency26n. The lack of sufficiency: a shortage, the state of having or being not...
• insupportable19adj. That cannot be tolerated or endured.
• insusceptible19adj. Not susceptible.
• intangibility19n. The quality or state of being intangible; intangibleness.
• integrability19n. The quality of being integrable (having an antidifference or...
• integumentary19adj. Of, related to, or composed of integuments.
• intelligencer16n. A bringer of intelligence (news, information); a spy or informant.
• intelligently17adv. In an intelligent manner.
• intentionally16adv. In an intentional manner; on purpose.
• interactional15adj. Of, pertaining to, or featuring interaction.
• interactively21adv. In an interactive manner.
• interactivity21n. The quality of being interactive.
• interbreeding17n. Breeding within a narrow range of individuals.
• intercalating16adj. That intercalates.
• intercalation15n. A period inserted into a calendar as in a leap year.
• intercellular15adj. Located between, or connecting, cells.
• interchanging20n. The act by which things are interchanged.
• intercolonial15adj. Between colonies.
• intercommunal19adj. Between communities or communes.
• intercondylar19adj. Between condyles.
• intercropping20n. The growing of two or more crops on the same field.
• intercultural15adj. Of, relating to, or between different cultures.
• interdistrict16adj. Between two or more districts.
• interestingly17adv. In an interesting way.
• interferogram19n. An image produced by using an interferometer.
• intergalactic18adj. Occurring between galaxies.
• intergranular14adj. Occurring along the boundaries between the crystals or grains of a...
• interlanguage15n. A language generated by a student of a foreign language that...
• interlocutory18adj. Of or pertaining to dialogue or conversation.
• intermarriage16n. Marriage between people belonging to different groups, such as...
• intermarrying19n. An intermarriage.
• intermembrane19adj. Between membranes.
• intermetallic17adj. Of, relating to, acting between, or comprising two or more metals.
• intermittency20n. The state of being intermittent; periodicity.
• intermountain15adj. Between mountains.
• intermuscular17adj. Between muscles.
• international13adj. Between or among nations.
• interobserver18adj. Between observers.
• interoception17n. Any of the senses that detect conditions within the body.
• interoceptive20adj. Of or pertaining to interoception or an interoceptor.
• interoperable17adj. (of a system or device) Able to communicate, and exchange data with...
• interparietal15adj. Between the parietal bones or cartilages.
• interparticle17adj. Between particles.
• interpersonal15adj. Between two or more people.
• interpolation15n. An abrupt change in elements, with continuation of the first idea.
• interposition15n. The act of interposing, or the state of being interposed; a being...
• interpretable17adj. Capable of being interpreted or explained.
• interproximal24adj. Between the proximal parts of two adjoining surfaces, but especially...
• interquartile22adj. Between quartiles.
• interracially18adv. Between races.
• interregional14adj. Of, pertaining to, or connecting two or more regions.
• interrelation13n. Mutual or reciprocal relation.
• interrogating15n. An instance of interrogating.
• interrogation14n. The act of interrogating or questioning; an examination by questions...
• interrogative17adj. Asking or denoting a question.
• interrogatory17n. A formal question or set of questions submitted to opposing party to...
• interruptible17adj. Able to be interrupted.
• intersectoral15adj. Between sectors.
• interspecific22adj. Occurring among members of different species; interspecies.
• intertemporal17adj. Describing any relationship between past, present and future events or...
• intertropical17adj. Between or within the tropics.
• intracellular15adj. Inside or within a cell.
• intracerebral17adj. Occurring or situated within the cerebrum.
• intracoronary18adj. Into or within the coronary artery or the heart.
• intracortical17adj. Within a cortex.
• intradermally19adv. In an intradermal manner.
• intralesional13adj. Having to do with the area inside a lesion.
• intramuscular17adj. Inside a muscle or the muscles.
• intransigence16n. Unwillingness to change one's views or to agree.
• intraparietal15adj. Within the wall of part of the body, especially within the parietal...
• intrapersonal15adj. Within the mind of an individual person.
• intraspecific22adj. Occurring among members of the same species.
• intrathoracic20adj. Within the thorax.
• intratracheal18adj. Within the trachea.
• intravascular18adj. Pertaining to anything inside blood vessels, including the internal...
• intravenously19adv. In an intravenous manner; by means of intravenous injection.
• intrinsically18adv. In an intrinsic manner; internally; essentially.
• introgression14n. The movement of a gene from one species to another.
• introspection17n. A looking inward; specifically, the act or process of self-examination...
• introspective20adj. Examining one's own perceptions and sensory experiences; contemplative...
• intrusiveness16n. The quality of being intrusive.
• intuitiveness16n. The state of being intuitive.
• inventiveness19n. The quality of being inventive; the faculty of inventing.
• invertibility21n. The condition of being invertible.
• investigation17n. The act of investigating; the process of inquiring into or following...
• investigative20adj. Of or pertaining to investigation or an investigation.
• investigatory20adj. Aimed at investigating.
• invincibility23n. The quality or state of being invincible; invincibleness.
• inviolability21n. The quality or state of being inviolable; inviolableness.
• involuntarily19adv. In an involuntary manner; done without conscious thought.

IO

• iontophoresis18n. A treatment in which electrodes are put in contact with tissue and a...

IR

• irrationalism15n. A philosophical movement formed as a cultural reaction against...
• irrationalist13n. A practitioner or adherent of irrationalism.
• irrationality16n. The state of being illogical or absurd.
• irrecoverable20adj. Not recoverable; incapable of being recovered.
• irrecoverably23adv. In an irrecoverable manner; beyond recovery.
• irreplaceable19adj. Incapable of being replaced, especially because of uniqueness or...
• irrepressible17adj. Not containable or controllable.
• irrepressibly20adv. In a manner or to a degree that can not be repressed; in an...
• irresponsible17adj. Lacking a sense of responsibility; performed or acting as though...
• irresponsibly20adv. In an irresponsible manner; so as to be irresponsible.
• irretrievable18adj. Not retrievable; irrecoverable; irreparable.
• irretrievably21adv. In an irretrievable manner; irrecoverably.

IS

• isoelectronic17adj. Having the same electronic configuration, although consisting of...
• isomerisation15n. The conversion of a compound into a different isomeric form.
• isomerization24n. The conversion of a compound into a different isomeric form.
• isometrically20adv. In an isometric manner.
• isoperimetric19adj. Having the same perimeter; applied to the problem of finding a plane...
• isoproterenol15n. Synonym of isoprenaline.
• isostatically18adv. In an isostatic manner.
• isostructural15adj. Having the same, or a corresponding, structure.
• isotropically20adv. In an isotropic manner; so as to exhibit the same properties or...

Questions about these words

How many thirteen-letter words that start with I are there?

Word.ws lists 261 thirteen-letter words that start with I, plus 1,374 rare ones.

What are common thirteen-letter words that start with I?

international, investigation, independently, institutional, inappropriate, intentionally, inspirational and inconvenience.

Which of the thirteen-letter words that start with I has the highest letter score?

inquisitively scores 28 points with the standard letter tile values.

Related word lists

• 13-Letter Words
• Words That Start with I
• 12-Letter Words Starting with I
• 14-Letter Words Starting with I
• Q Words Without U