countersue

verb

coun·​ter·​sue ˈkau̇n-tər-ˌsü 

variants or less commonly counter-sue

countersued also counter-sued also countersuing also counter-suing

transitive + intransitive

: to sue (someone) in return : to bring a counterclaim against someone

They were dissuaded from suing one another because they knew their target likely had patents that covered similar territory and they could be countersued quickly—the legal equivalent of mutually assured destruction.

—Steven Levy

Appellant countersued, alleging that respondent's interest charges were usurious and that he had breached his fiduciary duty to her.

—Peterson v. Gustafson, 584 N.W. 2d 660 (1998)

Examples of countersue in a Sentence

Recent Examples on the Web

The momager and Hunter denied the allegations laid out in the lawsuit and in the summer of 2023, Tiffany countersued for $30 million, per Insider, saying the mothers of the teenagers were trying to extort her. —Emily Krauser, PEOPLE, 15 Jan. 2026

Last week, Nike countersued Total90 LLC—which owns the federal trademark for Total90—and accuses it of bad faith conduct and fraudulently obtained trademark registrations. —Michael McCann, Sportico.com, 15 Jan. 2026

The Robsons denied that and, in September, countersued Iannaccone for defamation and abuse of the legal process. —Justin Wingerter, Denver Post, 25 Dec. 2025

The teams were originally suing for violations of two sections of the Sherman Antitrust Act, and NASCAR countersued the teams and Polk, alleging a conspiracy to collude with other teams during the negotiation process. —Jeff Gluck, New York Times, 1 Dec. 2025

Word History

First Known Use

1897, in the meaning defined above

Rhymes for countersue

• accrue
• ado
• ainu
• aircrew
• airscrew
• anew
• askew
• baboo
• babu
• bamboo
• beaucoup
• bijou