[ahy-dohnt-noh-nər], rhymes with "boner"
n., a penile erection of unknown origin and without provocation, usually occurring at an inappropriate time or in an awkward social setting (at church, at the blackboard in school, at grandma's house, etc.); see also MySpace Oddity
Check out these "I-don't-know-ner" Curb Your Enthusiasm clips:
- Hugging Auntie Rae (a classic)
And here's more from the mind of Larry David (from Curb, Season 4, "The Five Wood")