M.I.L.F

MILF, or ‘Mom I’d Like to Fuck’, is a slang word used to describe a sexually attractive middle-aged woman (usually, she is between 35-50 in age). A MILF is not necessarily an actual mother.

The word was popularized by the film American Pie:
While looking at a picture of Stifler’s mother:
MILF Guy #2: Dude that chick’s a MILF!
MILF Guy #1: What to hell is that?
MILF Guy #2: M-I-L-F Mom I’d Like to Fuck!
MILF Guy #1: Yeah dude! Yeah!