IPA: /kəmˈpleɪnər/
KK: /kəmˈpleɪnər/
A person who often expresses dissatisfaction or annoyance about something.
She is known as a complainer because she always finds something to criticize.
Complainer → It is formed from "com-" (meaning together) and "plangere" (meaning to lament or strike). The word describes someone who expresses dissatisfaction or laments about a situation, often in a collective context.
Think of people coming 'together' ('com-') to 'lament' ('plangere') about something — that's why a complainer is someone who voices their grievances.