ass
n. countable B2 Upper Intermediate US //ˈæs// ass
n. the part of the body that you sit on. It is a very informal and rude word for your bottom.
n. the buttocks or the posterior of a person. Highly informal and vulgar in register; frequently used in idiomatic expressions or as a general intensifier in American English.
He fell right on his ass.
The manager told him to get off his ass and start helping the customers.
Usage
Commonly used in idioms like 'pain in the ass' or 'get off one's ass'.
Pitfall
He is a pain in the arse (in US English)He is a pain in the assLearners often confuse the American spelling 'ass' with the British spelling 'arse'; 'ass' also refers to a donkey in neutral contexts.