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

• 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

The other two complainants in the criminal cases were from a glass and mirror provider and a custom cabinet builder who performed work on the Weatherford home. —Matthew Adams, Fort Worth Star-Telegram, 1 Aug. 2025

Horner was first cleared of the claims following an internal investigation and then again by a lawyer who dismissed the complainant’s appeal. —Ty Roush, Forbes.com, 9 July 2025

The complainants will meet with the mayor’s team, including potential city planning and housing departments, again next week, Wilson said. —Lizzie Kane, Chicago Tribune, 9 July 2025

The Folsom complainant references the potential damage from repeated and stressful sounds hundreds of times. —Ariane Lange, Sacbee.com, 23 July 2025

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