plaintiff

noun

plain·​tiff ˈplān-təf 

: a person who brings a legal action compare defendant

Did you know?

We won't complain about the origins of plaintiff, although complain and plaintiff are distantly related; both can be traced back to plangere, a Latin word meaning "to strike, beat one's breast, or lament." Plaintiff comes most immediately from Middle English plaintif, itself an Anglo-French borrowing tracing back to plaint, meaning "lamentation." (The English word plaintive is also related.) Logically enough, plaintiff applies to the one who does the complaining in a legal case.

Synonyms of plaintiff

• complainant
• accuser
• appellant

Examples of plaintiff in a Sentence

the judge ruled that the plaintiff's lawsuit was groundless, and he dismissed it

Recent Examples on the Web

Willy Wender Aceituno was already a plaintiff in a class-action lawsuit filed by the ACLU of North Carolina challenging the policy allowing warrantless immigration arrests after he was stopped twice in a span of minutes by immigration agents last November. —Andrea Castillo, Los Angeles Times, 26 May 2026

Looking at evidence from that trial, the court said plaintiffs challenging Alabama's map would probably be able to show the state legislature intentionally refused to create a second Black-majority district in an effort to dilute Black votes. —Aysha Bagchi, USA Today, 26 May 2026

The plaintiffs in the civil suit filed are Nancy Iskander and her husband Karim as well as son Zachary. —City News Service, Daily News, 26 May 2026

Collectively, the early lawsuits include about 70 plaintiffs. —Sean Emery, Oc Register, 26 May 2026

Word History

Etymology

Middle English plaintif, from Anglo-French, from pleintif, adjective

First Known Use

14th century, in the meaning defined above

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Kids Definition

plaintiff

noun

plain·​tiff ˈplānt-əf 

: the complaining party in a lawsuit

Legal Definition

plaintiff

noun

plain·​tiff ˈplān-təf 

: the party who institutes a legal action or claim (as a counterclaim) see also complainant, complaint, libellant compare defendant, prosecution

Etymology

Middle French plaintif, from plaintif, adj., grieving, from plaint lamentation, from Latin planctus, from plangere to strike, beat one's breast, lament