The definition of a counterclaim is a claim made to rebut accusations against you.(noun)
If you are sued for breaching a contract and you, in turn, also file suit against the plaintiff and claim thathe was really the one who breached the contract, your claim against the original plaintiff is an example of a counterclaim.
See counterclaim in Webster's New World College Dictionary
transitive verb, intransitive verb
See counterclaim in American Heritage Dictionary 4
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