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

Anderson has countersued and accused Burkle of smearing his reputation amid a separate business dispute. —Sacbee.com, 6 Mar. 2026

Twitter sued Musk to force him to complete the deal and Musk countersued. —Andrea Guzmán, Austin American Statesman, 4 Mar. 2026

Twitter sued Musk to force him to complete the deal, and Musk countersued. —CBS News, 4 Mar. 2026

Twitter sued Musk to force him to complete the deal, and Musk countersued. —ABC News, 3 Mar. 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