Meaning of the word "pain in the ass" in English

What does "pain in the ass" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

pain in the ass

US /peɪn ɪn ðə æs/
UK /peɪn ɪn ðə ɑːs/

Idiom

a person or thing that is annoying or causes problems

Example:
My little brother can be a real pain in the ass sometimes.
This paperwork is such a pain in the ass.