make fun of
Recorded 1737. Preserves the older meaning of fun, from Middle English fon, fonne (“foolish, simple, silly”), fun (c. 1700) meaning "a cheat, trick, hoax", from a verb fun meaning "to cheat, trick" (1680s).
- (idiomatic, informal) To tease, ridicule or make jokes about, generally in a pejorative manner.
- Please stop making fun of your sister and just help her!