The Oxford English Dictionary records: "the custom (in the 18th century prevalent in France and sometimes imitated in England) of going away from a reception, etc. without taking leave of the host or hostess. Hence, jocularly, to take French leave is to go away, or do anything, without permission or notice." OED states the first recorded usage as: 1771 SMOLLETT Humph. Cl. (1895) 238 "He stole away an Irishman's bride, and took a French leave of me and his master."
- A sudden or unannounced departure, or one taken without permission.
2010, William Marvel, The Great Task Remaining: The Third Year of Lincoln's War, pages 10:
- he may have felt a particular need to mitigate the responsibility of those who shirked their duty, for as he wrote that letter he had just returned from French leave himself.