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

• 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 plaintiffs argued that defense attorneys cannot legally present new facts when there has already been another trial that established a set of facts. —City News Service, Oc Register, 23 Sep. 2025

Overall, Jones was ordered to pay $965 million to the plaintiffs in the case, who also included relatives of the victims. —Alexander Mallin, ABC News, 23 Sep. 2025

The verdict, issued Friday at Garfield County District Court, is among the largest wrongful death awards for a single plaintiff in state history. —Emma Bussey, FOXNews.com, 23 Sep. 2025

Along with structural changes to Uber’s business model, the plaintiff is asking for all damages the law allows but did not name a specific dollar amount. —Stuart Dyos, Nashville Tennessean, 22 Sep. 2025

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