[Latin asininus, from asinus, ASS]
Of or pertaining to asses; asslike; stupid, obtinate.
Once, with no qualifying remarks, and in the ubiquitous red ink that seemed to grace all of my schoolwork, a teacher branded an essay I wrote as asinine. It confused me a little bit, as I wasn't sure what asinine meant, although contextually I was fairly sure it wasn't good; the humble dictionary put any confusion to rest. The following day, the same teacher called me aside and told me he had reconsidered his estimation of my work.
"Yes," he said. "It wasn't completely asinine, but that's only because it was completely half-assed."
To this day, I don't know which one of us was more asinine: me for not seeing that coming, or him for thinking about, planning and then setting up such a bad joke. On balance, I think it was him.