Grand Masti: Meaning and Double Meaning

Masti is fun. Grand is grand. Grand Masti is Grand fun.

Well, that's the under 18 version, the censored one. The movie was actually named Grand Masti because it sounds like Gaand Masti, which would literally mean 'Ass Fun', and is used as a slang, meaning cheap fun, something that is done for fun, but can land you in trouble. And hence the G*and Masti title.