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

In response, Baldoni countersued Lively, alleging that her allegations cost him $400 million. —Lara Walsh, InStyle, 11 Feb. 2026

Republic National countersued before the two settled outside of court at the end of 2024. —Lily O'Neill, San Antonio Express-News, 9 Feb. 2026

The Vann family countersued and their case was the only one to make it to trial. —Jane Harper, Dallas Morning News, 7 Feb. 2026

In late January, after Mayday countersued in a federal court in New York, that court temporarily blocked South Dakota’s actions. —Naomi Cahn, The Conversation, 6 Feb. 2026

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