underpants

Từ điển Oxford Advanced Learner 8th

under·pants [underpants] BrE [ˈʌndəpænts] NAmE [ˈʌndərpænts] noun plural
1. (also informal pants) (BrE)a piece of men's underwear worn under their trousers/pants
2. (NAmE)a piece of underwear worn by men or women under trousers/pants, a skirt, etc.
See also: ↑pants

Example Bank:
•He came to the door dressed only in his underpants.
•He sat on the examination table in his underpants.