-When a person, usually a female is angry and upset about something and starts whining/crying/yelling/screaming/throwing things when things don't go their way.
-Basically its going all PMSing and Godzilla like.
-Also can just be "BF" if you can't curse in front of certain people.
-Made famous by the Wayans Brothers comedy "White Chicks."

When a bitch goes crazy on something or someone

when someone pisses you off so much you just snap and start flipping the fuck out

you do NOT want to be near someone when they have a bitchfit

When a girl goes crazy and starts yelling.

When a person of the female or male species throws a temper tantrum. They throgh a hissy fit and act like a bitch, hence "bitchfit." Or when a bitch gets feisty.

When a chick goes crazy and mad.

This usualy happens when a girl has had a very bad day and some thing just pushes her over the edge. Then she goes and does some thing totaly nasty, uncalled for and bitchy to some one who didn't deserve it. These sitations should be avioded at all times.