1. 爱发牢骚的人, 老是抱怨的人 (名)：complainant 发牢骚的人; 原告 (名) | complainer 爱发牢骚的人, 老是抱怨的人 (名) | complaint 诉苦; 牢骚; 抱怨 (名)
1. The complainer would be required to show evidence related to the complaints they have lodged about the public servant's alleged failings.
2. " I was the biggest complainer you could ever meet, " he said.