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
• suer

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 complainant, 46-year-old Onisim Dorneanu of Wisconsin, until recently owned a total of 16 units in the building and lived in one of the units part-time, according to the filing. —Caroline Kubzansky, Chicago Tribune, 19 Mar. 2025

You’re done with this matter — and so am I. Jerald Fuller, Coconut Creek (Editor’s Note: Fuller was the complainant in the ethics complaint against Tony, filed in 2022). —Sun Sentinel Editorial Board, Sun Sentinel, 8 Mar. 2025

The complainants have demanded the group be stopped from issuing further threats, requesting the court for a jury trial. —Ailia Zehra, The Hill, 8 Feb. 2025

Soon after making the report to police, the complainant received an alert from FedEx explaining that the merchandise would be delivered to and held for pick up at a Walgreens location in neighboring Skokie, according to the release. —Pioneer Press, Chicago Tribune, 28 Mar. 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