A person who is so stupid that any attempt to get them to understand
common sense and/or decent
human behavior is all but futile, and is as if you are talking to an actual ape. Almost
always used in an aggressive or hostile way.
"
Cassandra will fall
in love with me one day, I know it for sure!"
"You've been saying that for over a year and she's made it very clear that she wants nothing to do with you. Get a grip, you
fucking ape"