adj. (slang): A combined state of mental agitation and physical volatility. It's use may provide warning that the individual it describes has lost all self-control and cannot be reasoned with. Can refer to either a chronic or temporary condition.
by maximo hudson January 19, 2009

Family: "So, did he have a psychotic break? Or is he manic/depressive?"
Doctor: "No. I'm sorry. Your son is bat shit crazy."
Doctor: "No. I'm sorry. Your son is bat shit crazy."
by Brainiac March 02, 2005

by Lorraine Bates July 30, 2006

Crazy to a degree bordering on complete insanity. The state in which one makes decisions which make the exact opposite of sense.
See also: bat-shit
See also: bat-shit
by DJ Bitterbarn August 11, 2004

One step beyond just plain crazy. It is usually a temporary thing...sparked by something unexpected, or just really awful.
by ithaqua April 13, 2003

Some one who is so off the wall insane that they just do the dumbest, most immature, revolting things.
by Ouch! Don't do that March 21, 2010

Whoa Nelly! Did you overhear their conversation this morning....Those girls are Bat-shit crazy!
I wonder what's wrong with those girls? They seem to have gone bat-shit crazy.
I wonder what's wrong with those girls? They seem to have gone bat-shit crazy.
by Demands James December 30, 2016
