A state of anger and rage that produces behavior more closely resembling that of an enraged ape than a human.
From the habit of enraged apes of flinging their own feces at their object of anger (if you haven't experienced this phenomenon first hand consider yourself blessed).
Billy-Bob went apeshit when Jimmy-Joe puked up four moon pies on his '68 Dodge Dart.
Really going crazy or nuts over or about something.
Dan is going ape shit about how cool his new car is. Or - Dan went ape shit when he found out his wife left him.
adj. An undignified loss of control, as in "To go apeshit".
"After losing the election, George went apeshit, trashing the Oval Office, the War Room, and the Clinton Memorial Bedroom."
To flip out on someone or go crazy.
Sally went ape shit when I pulled it out of her ass and hit her in the face with it.
to act in an insane manner.
I told Rob I slept with his girl and he went ape shit on me.
Extreme anger or a state of insanity stemming from anger. When someone goes fucking crazy.
Donkey Kong went completely apeshit when King K Rool stole all the bananas from his cave.
To loose all sense of reason. Said apeshitter will often start to speak in some strange language where the only recognisable words are "fuck" and other curses.