The open space in a girl's crotch when the girl is so thin she cannot shut her legs all the way, leaving a gap in her crotch in which people can see through.
Calpie (Cal-Pee) "Eww dude! Look at her CALPIE! it's sooo wide!" or "Whoa that calpie's soo big I could fit my fist through it and she couldn't tell!"
by JoeeeOhhThoo June 10, 2009