Official:
1.
Something utterly ridiculous or lacking sense.
2.
Something relating to or resembling an ass.
Slang:
1. The act of being an asshole.
2. The act of being a
retard.
3. The act of being stupid.
4. The act of being ignoramus.
Official:
1. That's an asinine plan.
2. That piece of "art" is asinine.
Slang:
That
guy's asinine, in all meanings of the
word.