asinine

adj

1. Very foolish; failing to exercise intelligence or judgement or rationality.

   “They danced on silently, softly. Their feet played tricks to the beat of the tireless measure, that exquisitely asinine blare which is England's punishment for having lost America.”

2. Characteristic of an ass (an asshole): objectionably inconsiderate or jerky.

   “Philo Vance is an asinine jerk - a rude, Nietzschean snob who holds most of the people he meets and the things he sees in utter disdain. He's an insufferable smarty-pants, always convinced he's right and that everyone else is wrong. Of course, he is right, but that doesn't make him any less of a jerk.”

3. Of, pertaining to, or characteristic of donkeys.

   “Don Quixote had put himself but a little way ayont the village of Don Diego, when he encountered two apparent priests, or students, and two husbandmen, who came mounted on four asinine beasts.”