bippy
/ˈbɪpɪ/noun
(pl. -ies)
- US informal a person's buttocks〈美, 非正式〉（人的）屁股, 臀部。
词源
1960s: popularized by the US television programme Rowan & Martin's Laugh-In, where it was used as a nonsense word with an air of innuendo but intentionally vague meaning: of unknown origin.