What is Crotch?

Crotch definition and meaning on Dictionary terms:
a forking or place of forking, as of the human body between the legs.
the part of a pair of trousers, panties, or the like, formed by the joining of the two legs.
a piece of material serving to form a juncture between the legs of trousers, panties, etc.
a forked piece, part, support, etc., as a staff with a forked top.
Billiards. an area 4