A dude who is quick to go ape shit and is easily pissed off without warning. This dude goes quietly about his day then goes wild unexpectedly. Similarly seen in nature when a real silver backed ape is lazing about within the jungle until some tiny thing unexpectedly sets him off. Stay clear!
Nick totally became a silver backed ape when he saw his old girlfriend with a new dude.
the state of being in which a man and a woman are in a position in both are facing forward; where one is pressing their ass against the other, in a grinding motion, until eventually one of the individuals is "backed" into a wall, and pinned; wherefore, the grinding usually continues even more vigorously.
Guy 1: Did you see Isaac at that last party?
Guy 2: You mean did I see Isaac get backed at that party!