1. Describing an action that only one who comprises of ass-like characteristics would perform.
Guy #2: Man that is so assanine. I would have left the match rather than continue to play with that asshole all day.
or in a absurd conflict with a person(s)
this is total assanine when u get busted with a friend or 2 (the situation)
this conversation is assanine (when talking to someone in a absurd conflict)