Words That Start with OO

There are 35 words that start with OO on Word.ws, from 2 to 12 letters. The most common length is 3 letters (8 words). The words used most often are ooh, oops, oo, oooh and oof.

Meanings from Wiktionary. Not an official Scrabble, Words With Friends or Wordle word list.

2-letter words that start with OO

oo2n. Any of four Hawaiian birds of the genus Moho, formerly classed with the...

3-letter words that start with OO

oof6interj. A sound mimicking the loss of air, as if someone's solar plexus had...
ooh6interj. An expression of surprise.
ook7interj. Used to represent the sound of the cry of an ape or monkey.
ool3n. A swimming pool into which urinating is not allowed.
oom5n. An older man, especially an uncle. (Frequently as a respectful form of...
oon3n. An oven.
oop5interj. Used to acknowledge a small mistake or accident.
oot3pron. Anything.

4-letter words that start with OO

oooh7interj. Elongated form of ooh.
oops6interj. Used to acknowledge a small mistake or accident.
oose4n. Fluff, particularly from a textile source such as cotton or wool.
ooze13n. Tanning liquor, an aqueous extract of vegetable matter (tanbark, sumac...
oozy16adj. Of or pertaining to the quality of something that oozes.

5-letter words that start with OO

oodle6n. A crossbreed of a poodle and another breed of dog.
oomph12n. Strength, power, passion or effectiveness; clout.
oontz14n. The game of craps.
ooooh8interj. Elongated form of ooh.
oopsy10interj. Synonym of oops.
oorah8interj. The official yell for the US Marines.

6-letter words that start with OO

oocyst11n. A thick-walled spore in the lifecycle of some parasitic protozoans that...
oocyte11n. A cell that develops into an egg or ovum; a female gametocyte.
oodles7n. Unspecified large amount, number, or quantity; lots, tons.
oohing10n. An ooh sound.
oolite6n. A rock consisting of spherical grains within a mineral cortex accreted...
oolong7n. A partially fermented tea, often roasted, which combines the...
oompah13v. To produce an oom-pah sound.
oozing16n. Something that oozes; a seepage.

7-letter words that start with OO

oobleck15n. A mixture of cornstarch and water with unusual physical properties.
oolitic9adj. Made up of, or containing oolites.
oopsies9v. Oops.
ootheca12n. An egg case of any of the orthopteroid insects (such as cockroaches and...

8-letter words that start with OO

oomycete15n. Any of a number of filamentous unicellular protists of the class...

9-letter words that start with OO

oogenesis10n. The formation and development of an oocyte or ovum.

12-letter words that start with OO

oophorectomy24n. The surgical removal of one or both ovaries, usually performed to treat...

138 rare words that start with OO

Questions about these words

How many words that start with OO are there?: Word.ws lists 35 words that start with OO, plus 138 rare ones.
What are common words that start with OO?: ooh, oops, oo, oooh, oof, oop, ooooh and oozing.
Which of the words that start with OO has the highest letter score?: oophorectomy scores 24 points with the standard letter tile values.

Related word lists

Word lists and meanings adapted from the Wiktionary entry of each word. Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws left out names, abbreviations, misspellings and offensive words, and ordered the most common words by how often they appear in English (wordfreq). Meanings from Wiktionary; this is not an official Scrabble, Words With Friends or Wordle word list. Wiktionary data of 2026-09-02.

Cite this page: “Words That Start with OO: 35 Words by Length.” Word.ws, https://word.ws/words/starting-with-oo. Based on Wiktionary, CC BY-SA 4.0.