noun
buttock; butt cheek
Rare term for the fleshy part of the buttocks; more common words are お尻 or 臀部 (でんぶ).
彼は椅子から落ちて尻たぶを打った。
He fell off the chair and hit his buttock.
Compound of 尻 (しり, 'buttocks') and たぶ, a dialectal or colloquial word for a plump, rounded part, possibly related to たぶら (plump). The exact derivation is uncertain.