Counterclaim (noun)

1. A claim made in opposition to another claim.
2. A statement made in response to an opposing statement, in which the truth of the latter is denied or disputed.

Origin:

Derived from the combining of the words "counter" (against) and "claim" (a statement asserting that something is true or factual).

Examples:

1. The defendant made a counterclaim of defamation against the plaintiff.
2. The company's counterclaim was that they had not infringed on any patents.
3. In a counterclaim, the defendant argued that the plaintiff had breached the contract.
4. She filed a counterclaim for damages.
5. The counterclaim was that the plaintiff had no legal standing to bring the suit.