The story
- Latin · borrowed fromet tū, Brūte
- English todayet tu, Brute
Borrowed from Latin et tū, Brūte (literally “and you, Brutus”). Used figuratively from 1591 (sometimes jocularly) to express shock and sadness at the treachery of a good friend. Although apparently an Elizabethan invention, a “genuine antique reproduction”, it appears to have been well known in England before its use in Shakespeare's Julius Caesar.
Etymology from Wiktionary, CC BY-SA 4.0.