complainant

noun

com·​plain·​ant kəm-ˈplā-nənt 

1

: the party who makes the complaint in a legal action or proceeding

2

: one who complains

Synonyms of complainant

• plaintiff

Examples of complainant in a Sentence

the complainant charged that the defendant had broken the ironclad contract that both had signed

Recent Examples on the Web

Someone has to interview the complainant, the accused and any witnesses, usually within days. — Beth Worthy, Forbes.com, 1 Oct. 2026

The average reported loss among complainants 60 and older was approximately $38,500, and nearly 12,500 people in that age group reported losing more than $100,000. — Angela Ramos, The Conversation, 29 Sep. 2026

The complainant and respondents had the opportunity to testify and present evidence. — Mahsa Saeidi, CBS News, 28 Sep. 2026

Rupnik, who maintains his innocence, is facing a church trial in the Vatican, which complainants say is taking too long and lacks transparency. — Christopher Lamb, CNN Money, 28 Sep. 2026

Word History

First Known Use

15th century, in the meaning defined at sense 1

Kids Definition

complainant

noun

com·​plain·​ant kəm-ˈplā-nənt 

1

: one who makes a legal complaint

2

: one who complains

Legal Definition

complainant

noun

com·​plain·​ant kəm-ˈplā-nənt 

: the party (as a plaintiff or petitioner) who makes the complaint in a legal action or proceeding