Acronym meaning Mother I'd Love to Fuck. Used to describe a physically / sexually attractive woman of an age likely to have teenage sons of her own (generally 35-50). Term widely used by said teenage sons, most often in reference to each other's mothers. When with their Boyz, they joke about MILFs... privately, they go home and fap themselves rotten thinking about the MILFs they just joked about.
"Dude... J-Dogg's moms got an ass you want to eat lunch from! Total MILF!"