Meaning of the word complainer in English

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

complainer

US /kəmˈpleɪnər/
UK /kəmˈpleɪnər/

Noun

a person who complains, especially frequently or habitually

Example:
He's such a constant complainer, nothing ever satisfies him.
The restaurant staff are used to dealing with complainers.