mercurial

Syllables: mer·cu·ri·al/məːˈkjʊə.ɹɪ.əl/US/mɝˈkjʊ.ɹi.əl/

mercurial noun: any of the plants known as mercury, especially the annual mercury or French mercury (Mercurialis annua).

Noun

mercurial (plural mercurials)

(obsolete) Any of the plants known as mercury, especially the annual mercury or French mercury (Mercurialis annua).
A person born under the influence of the planet Mercury; hence, a person having an eloquent, quickwitted, furtive, or volatile character.
- As for [Lambert] Simnell, there was not much in him, more then that hee was a handſome Boy, and did not ſhame his Robes. But this Youth (of whom wee are now to ſpeake) was ſuch a Mercuriall, as the like hath ſeldome beene knowne; and could make his owne part, if at any time hee chanced to bee out.1622, Francis, Lord Verulam, Viscount St. Alban [i.e. Francis Bacon], The Historie of the Raigne of King Henry the Seventh, […], London: […] W[illiam] Stansby for Matthew Lownes, and William Barret...
A chemical compound containing mercury.
(historical) A preparation of mercury, especially as a treatment for syphilis.
- She had paſſed through the milder Remedies frequently without ſucceſs: upon which account I deſigned Mercurialls; and beginning with Venæſection, afterwards purged her with decoct. epithymi, as it is preſcribed in the method of Cure. [...] After I had thus evacuated the Plethora, and diſpoſed her...1676, Richard Wiseman, “Of Lepra, or Elephantiasis”, in Several Chirurgicall Treatises, London: Printed by E. Flesher and J[ohn] Macock, for R[ichard] Royston […], and B[enjamin] Took […], →OCLC, 1st...
- [A] small dose of the mercurial may cause excessive salivation; and, if this discharge be attended by much soreness of throat, it is most difficult to determine whether the salivation is actually the result of the mercurial, or merely symptomatic of the sore throat and cold. If it proceed from the...1858, James Copland, “POISONS—Poisoning—Poisoned—Symptoms and Treatment of”, in A Dictionary of Practical Medicine. […] In Three Volumes, volume III, part I, London: Longman, Brown, Green, Longmans...

Adjective (1)

mercurial (comparative more mercurial, superlative most mercurial)

(comparable) Having a lively or volatile character; animated, changeable, quick-witted.
- his mercurial temperament
- [Y]our Mercuriall wit hath mangonized a Gigantean fury with an humble hue.1642, Thomas Barton, “Section II”, in ΑΠΟΔΕΙΞΙΣ ΤΟΥ ΑΝΤΙΤΕΙΧΙΣΜΑΤΟΣ. [APODEIXIS TOU ANTITEICHISMATOS.] Or, A Tryall of the Covnter-scarfe, Made 1642. […], London: Printed by Thomas Purslow, for...
Synonyms:

fickle, unpredictable
(not comparable) Pertaining to the astrological influence of the planet Mercury; having the characteristics of a person under such influence (see adjective sense 1).
- The Sun to the Terms of Mercury. It inclineth the native to be Mercurial, given to ſtudy Arts and Sciences, and to delight in reading, and to follow his Calling with chearfulneſs.1682, Joseph Blagrave, “[The Effects of Directions.] The Sun Directed unto Promittors.”, in Obadiah Blagrave, editor, Blagrave’s Introduction to Astrology. In Three Parts. […], London: Printed by E....
- 6thly, The ☽ separates from a △ of ♂︎, and applies to ☍ of ☿, lord of the 3d; which intimated that some neighbour of the querent, either with a letter, words, or cross information, would wholly destroy the querent's hopes; and that mercurial men, viz. scholars or divines, would be his enemies: [...]1852, William Lilly, Zadkiel [pseudonym; Richard James Morrison], “Of the Ninth House and Its Questions. Long Journeys, Voyages, Arts, Science, Church Preferment, Law, &c.”, in An Introduction to...
(not comparable) Pertaining to the planet Mercury.
(not comparable) Of or pertaining to the element mercury or quicksilver; containing mercury.
- Beware alſo of Mercuriall lotions, I meane any which haue Mercurie Sublimate Precipitat or otherwiſe prepared in them, for though they haue good qualities, yet they are vpon my knowledge and experience dangerous, [...]1617, John Woodall, “Of the Small Siringe”, in The Svrgions Mate, or A Treatise Discouering Faithfully and Plainely the due Contents of the Svrgions Chest, the Uses of the Instruments, the Vertues...
- [...] Dr. Francis Fuller, [...] upon wearing a Quick-ſilver Girdle, for the Cure of the Itch, (and that after an inconſiderate and raſh manner) was brought under a violent Spaſmodick Diſtemper, which was ſupposed by himſelf and others to be owing to ſome Mercurial Particles lodg'd in ſome excretory...1734, T[homas] K[night], A Critical Dissertation upon the Manner of the Preparation of Mercurial Medicines, and Their Operation on Human Bodies; particularly Those Most in Fashion: […], London...
(not comparable) Caused by the action of mercury or a mercury compound.
- I ſaw in the Year 1709. a notable inſtance, where a Phyſician order'd the Patient to be Bled five times in a Mercurial Salivation in a Caſe not Venereal; when he did ſpit at the rate of ℔ iv. per diem, and it was at the height, and yet notwithſtanding it did continue for all this, and the Patient...1712, J. White, “Farther Indications of Right Blood-letting in Fevers, […]”, in De Recta Sanguinis Missione: Or, New and Exact Observations of Fevers. […], London: Printed by D[aniel] Brown[e] […]...
- The last exciting cause of the mercurial ulcer, which I shall now mention, is the use of the knife or of the caustic, during a mercurial course, to wounds made or enlarged at this time; for the great additional irritation, which the operation must produce, disposes such wounds to take on easily the...1810, Andrew Mathias, “Section II. The Exciting Causes of the Mercurial Disease.”, in The Mercurial Disease. An Inquiry into the History and Nature of the Disease Produced in the Human Constitution...
(Roman, not comparable) Pertaining to Mercury, the Roman god of, among other things, commerce, financial gain, communication, and thieves and trickery; hence (comparable), money-making; crafty.
- Near-synonym: Hermesian
- I know the ſhape of's Legge: this is his Hand: / His Foote Mercuriall: his martiall Thigh / The brawnes of Hercules: but his Iouiall face— / Murther in heaven?1611 April (first recorded performance), William Shakespeare, “The Tragedie of Cymbeline”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard...
Synonyms:

Hermesian

Adjective (2) capitalized: Mercurial

Mercurial (comparative more Mercurial, superlative most Mercurial)

Alternative letter-case form of mercurial.
- He firſt ſubſiſts in Jupiter, the artificer of the world; next, among the ſupermundane gods; in the third place, among the liberated gods; fourthly, in the planet Mercury; fifthly, in the Mercurial order of demons; […] Likewiſe in this city a certain man once flouriſhed, full of the Mercurial...1792, The Phædrus of Plato; a Dialogue Concerning Beauty and Love, London: […] Edward Jeffery, […]; R. Faulder, […]; J. Cook, […]; and T. and J. Merrill, […], page 126
- The alchemists too spoke of the return of the Mercurial spirit as a ‘celestial rain’, or ‘dew’ (Norton’s stilla roris madidi, Dee’s ros caeli), a ‘divine water’ falling from the ‘heaven’ of the vessel to reanimate the blackened earth of the Stuff.1980, Charles Nicholl, “The Transmutation of King Lear”, in The Chemical Theatre, London; Boston, Mass.; Henley-on-Thames: Routledge & Kegan Paul, →ISBN, section “The dew”, page 205

mercurial meaning in Arabic and Vietnamese

mercurial in Arabic

having a lively or volatile character — see also animated, changeable, quick-witted: حَامِي الطَّبْع ḥāmī ṭ-ṭabʕ, مِزَاجِيّ mizājiyy

mercurial in Vietnamese

having a lively or volatile character — see also animated, changeable, quick-witted: lanh lợi

Examples of mercurial in a sentence

If it proceed from the mercurial, there will generally be some tenderness of the gums, a soft and flabby state of the sides of the tongue, and it will generally be more obstinate.1858, James Copland, “POISONS—Poisoning—Poisoned—Symptoms and Treatment of”, in A Dictionary of Practical Medicine. […] In Three Volumes...
Lebanon has shown once again that it is a land of dazzling deals and mercurial personalities, including in the realm of the national presidency itself.2016 October 22, Rami G[eorge] Khouri, “Lebanese Oligarchy Preserves Its Interests Once Again”, in Al Jazeera, archived from the original...
Netanyahu the first time around: his intensely personal, if often mercurial, approach to political relationships.2024 October 24, Ned Temko, “Netanyahu has high hopes of Trump. Might he be mistaken?”, in The Christian Science Monitor:

Synonyms of mercurial

Forms of mercurial

Noun
plural	mercurials
alternative form	mercuriall
Adjective
comparative	more mercurial
superlative	most mercurial
alternative form	Mercurial
comparative	more Mercurial
superlative	most Mercurial

Plural of mercurial: mercurials

Origin of mercurial

Noun sense 1 (“(obsolete) plant known as mercury”) is from Middle English mercurial (“a plant, probably the goosefoot (Chenopodium); (possibly) dog’s mercury (Mercurialis perennis)”), from Anglo-Norman mercurial, Old French mercurial, or directly from their etymon Latin mercuriālis (“a plant, probably annual mercury (Mercurialis annua)”), short for herba mercuriālis (“(probably) annual mercury”, literally “herb or plant of the god Mercury”). Mercuriālis (“pertaining to the Roman god Mercury”, adjective) is derived from Mercurius (“the Roman god Mercury”) + -ālis (suffix forming adjectives of relationship from nouns). Later adjective and noun uses may have been directly derived from Latin mercuriālis (adjective), whence Middle English mercurial (“under the astrological influence of the planet Mercury”).

Words formed from mercurial

Phrases with mercurial

mercurial fingers

Questions about mercurial

What does mercurial mean?: Mercurial means any of the plants known as mercury, especially the annual mercury or French mercury (Mercurialis annua).
What is mercurial in Arabic?: Mercurial in Arabic is حَامِي الطَّبْع (ḥāmī ṭ-ṭabʕ), مِزَاجِيّ (mizājiyy). See Mercurial meaning in Arabic.
How do you use mercurial in a sentence?: If it proceed from the mercurial, there will generally be some tenderness of the gums, a soft and flabby state of the sides of the tongue, and it will generally be more obstinate.
What part of speech is mercurial?: Mercurial can be a noun or an adjective.
How do you pronounce mercurial?: Mercurial is pronounced /məːˈkjʊə.ɹɪ.əl/ (UK).
What is the plural of mercurial?: The plural of mercurial is mercurials.

Words near mercurial in the dictionary

Adapted from Wiktionary: mercurial (page history and authors); Mercurial (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated: 2026-09-02

Pronunciation audio from Wikimedia Commons, each file under its own free license: En-uk-mercurial.oga.

Cite this entry: “mercurial.” Word.ws, https://word.ws/mercurial. Based on Wiktionary, CC BY-SA 4.0.