also: きょしり
noun
large buttocks; big butt
Colloquial term, often used for women. Can be playful or mildly vulgar depending on context.
彼女は巨尻がコンプレックスだと言っている。
She says she has a complex about her large buttocks.
あのモデルは巨尻で有名だ。
That model is famous for her big butt.
Compound of 巨 (きょ, 'huge') and 尻 (しり, 'buttocks'). The reading きょじり is a straightforward combination, while きょしり may be a variant or influenced by rendaku.