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