1To have sexual intercourse.
2To have sexual intercourse with (a person).
3To swindle or cheat (a person).
1920s; earliest use found in Ernest Hemingway (1899–1961), writer. From Yiddish yentsen to copulate from yents (euphemistic) the penis, literally ‘that thing’ from Middle High German jenes, neuter singular of jener, with development of an epenthetic consonant in Yiddish.