memo

Etymology

It is a shortening of memorandum,^[2][3][4][5] first as a written abbreviation.^[3] That word is Latin memorandum (“(a thing) to be remembered”), the neuter of memorandus (“worth remembering”), the gerundive of memorō (“to call to mind”),^[2][6] from memor (“mindful”), from Proto-Indo-European *(s)mer- (“to remember”).^[2]

Earliest recorded meaning

A note of something to be remembered, a memorandum: 1705, in a letter of John Mordaunt.^[3][4] Etymonline and Barnhart date it only from 1889.^[2][5]

Semantic evolution

For a long time memo was a colloquial form, but the OED notes that it is now normally used instead of memorandum except in very formal contexts such as law and diplomacy.^[3] Its commonest use is for a short written message sent within an organization.^[7][8] The verb, to send a memo to someone or to set something down in one, appears in 1961.^[3][4] In American use from the 1980s, phrases such as didn't get the memo joke that someone is unaware of what everyone else knows.^[3][9]

Timeline

• 1705 – a memorandum.^[3][4]
• 1889 – first date in Etymonline and Barnhart.^[2][5]
• 1961 – the verb, to send a memo to someone.^[3]
• 1985 – didn't get the memo, unaware of something.^[3]

Modern meaning

Noun

1. A short written message sent from one person or department to another within an organization; a memorandum.
2. A note made to help one remember something.

Verb

1. To send a memo to someone, or to set something down in one.

Word family

• countermemo

Related words

• memorandum
• memory
• memorable
• remember

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
3. ^ a b c d e f g h i Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
4. ^ a b c d Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
6. ^ The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
7. ^ Collins English Dictionary (2023), Glasgow: HarperCollins
8. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
9. ^ Green, Jonathon (2010), Green's Dictionary of Slang, London: Chambers; digital ed. 2016–, https://greensdictofslang.com