In
Cleveland, 9 times out of ten it means to
lie,
front or bullshit. In noun form, a liar, or bullshitter.
Girl 1: I went to the
mall and this dude gave me a discount on my Forces cuz I told him he was cute.
Girl 2: You cappin'!
- - - - - - - - -
Boy 1: Last
Saturday, I got pussy from 3 different girls.
Boy 2: Man,
youse a cap.