Of or owned by or obtaining the characteristics for the butt as stupidity and obstinacy
- incredibly ridiculous or stupid
- Of or belonging to, or having the qualities of, the ass, as stupidity and obstinacy.
c.1600, "obstinate, stupid," from Latin asininus "stupid," actually "like a butt," from asinus "ass," also "dolt, blockhead" (see butt (n.1)). The literal good sense in English is recorded from 1620s.
(a.) Of or owned by, or getting the characteristics of, the butt, as stupidity and obstinacy.