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

The plaintiff, identified as Jane Doe, is seeking monetary damages and a jury trial. —Lexi Nicklaus, Baltimore Sun, 28 Apr. 2026

The plaintiffs took legal action to challenge the ban in November 2023, and have now officially been transferred their winnings. —Jackson Thompson, FOXNews.com, 28 Apr. 2026

On Monday, Gregory Craig, the attorney for the National Trust, wrote to Assistant Attorney General Breet Shumate, who had urged the plaintiffs to drop the case, citing the events at the Correspondents’ Dinner. —Ted Johnson, Deadline, 28 Apr. 2026

The plaintiff demands that the court remove Altman from OpenAI’s board and roll back its for-profit status. —David Zimmermann, The Washington Examiner, 28 Apr. 2026

Word History

Etymology

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

First Known Use

14th century, in the meaning defined above

Podcast

Get Word of the Day delivered to your inbox!

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