Horny Without A Cause
Used most often as "HWACin'" to describe the state of someone when they are fucking around, cheating, hooking up or partaking in any other frequent sexual behavior as a hobby or just because they can.
Also, horny bitches who don't care about the who, what, when or where, just as long as they are hooking up.
She hooked up with eight ugly guys and in one night? Man, she was really HWACin'.