moo

Etymology

It is imitative of the sound a cow makes.^{[2][3][4][5][6][7][8]} The OED compares other imitative words for lowing, such as French mugir, Latin mūgiō, German muhen (15th century) and Lithuanian mūkti,^[2][7] and the interjections German muh, French meuh and Spanish mu;^[2] Etymonline and Weekley cite the Latin verb as well,^[7][9] and Etymonline also Middle High German mūhen (“to low, bellow”).^[7] The noun comes from the verb.^[8][2]

Earliest recorded meaning

Of a cow, to make its deep, drawn-out cry; to low: about 1550, in the Complaynt of Scotland.^[2] Merriam-Webster dates the verb to 1548 and Barnhart to 1549;^[3][8] Etymonline gives the 1540s.^[7]

Semantic evolution

The verb was later used of people making a sound like a cow's.^[2][10] The noun for the cow's cry is not recorded until 1789, in Davidson's Seasons,^{[2][8][7][11]} and the word used as an interjection imitating the sound from 1845.^[2] The baby-talk moo-cow, a cow, is recorded from 1812,^[7] and moo alone for a cow from 1930, chiefly in North America and Australia.^[2] In British English the noun became an insult for a woman, usually in silly old moo:^[2][12] Green's Dictionary of Slang finds it in 1909 and ties it to moo-cow,^[12] and the phrase became well known through the BBC comedy Till Death Us Do Part in the 1960s.^[12] In the English dialects the verb and the noun were common from Scotland to Somerset, and in west Somerset the word was used only to children;^[11] moo-moo was a child's name for a cow.^[11]

Timeline

• c. 1550 – verb, of a cow, to low.^[2] Merriam-Webster dates it to 1548.^[3]
• 1789 – noun, the cry of a cow.^[2][8][7]
• 1812 – moo-cow, baby talk for a cow.^[7]
• 1845 – interjection imitating the sound.^[2]
• 1909 – a woman, especially a foolish one.^[12] The OED's first example of this sense is from 1967.^[2]
• 1930 – colloquially, a cow.^[2]

Meanings

Verb

1. Of a cow or similar animal, to make its deep, long cry; to low.^[13][3][2]
2. Of a person, to make a sound like this, or to say something in such a voice.^[2][3]

Noun

1. The deep cry of a cow, or an imitation of it.^[3][2]
2. (informal, chiefly North American and Australian) A cow.^[2]
3. (British, derogatory) A woman regarded as foolish or useless, usually in silly old moo.^[2][12]

Interjection

1. Imitating the sound a cow makes.^[13][2]

Word family

• moo juice

Related words

• moolah

Usage notes

A separate slang moo, money, is a shortening of moolah, recorded in the US from 1941 (Green's Dictionary of Slang has it in 1942).^[2][10][12]

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
4. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
5. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
6. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
7. ^ a b c d e f g h i Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
9. ^ Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
10. ^ a b Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
11. ^ a b c Wright, Joseph, ed. (1898–1905), The English Dialect Dictionary, 6 vols., Oxford: Henry Frowde; via EDD Online 4.0, University of Innsbruck (CC BY 4.0)
12. ^ a b c d e f Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com
13. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins