A term playing off of
MILF (Mother I'd Like to Fuck) except the G stands for one of many things: Grandmother,
Grandfather, Girl, or
Guy. As such it can be used as a gender neutral term.
"Damn that
dude is such a GILF, I'd pay money for a piece of that
change"
OR
"Holy
shit that old lady must bathe in the fountain of youth, totally a GILF"