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

Fong declined to specify the nature of the allegations or identify complainants, beyond confirming that the accusations were unrelated to either Gomez or Henrich. —Pj Green, Kansas City Star, 16 Jan. 2026

The complainant alleged that Young yelled and became hostile before striking them in the chest with a closed fist while the vehicle was stopped. —Wbff Staff, Baltimore Sun, 13 Jan. 2026

Currently, the Police Oversight office allows complainants to resolve more minor complaints, like when an officer is rude, by asking that the officer's supervisor to talk to them about their conduct. —Austin Sanders, Austin American Statesman, 12 Jan. 2026

One of the five complainants is an HHS employee who needs a top surgery revision and to continue hormone therapy. —Theresa Gaffney, STAT, 5 Jan. 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