A more thorough explanation:

A permissive counterclaim is a type of legal claim that a defendant can bring against a plaintiff in a lawsuit. This type of claim is different from a compulsory counterclaim, which arises from the same transaction or occurrence as the plaintiff's claim.

For example, let's say that a plaintiff sues a defendant for breach of contract. The defendant could file a permissive counterclaim against the plaintiff for a completely different issue, such as defamation or negligence. This type of counterclaim is "permissive" because it is not required to be brought in the same lawsuit as the plaintiff's claim.

If the defendant chooses not to raise the permissive counterclaim in the current lawsuit, they are not waiving their right to bring an independent action on the claim at a later time.

Another example of a permissive counterclaim could be a defendant in a personal injury lawsuit filing a counterclaim against the plaintiff for property damage that occurred in a separate incident.

Overall, a permissive counterclaim allows a defendant to bring a claim against a plaintiff that is not directly related to the current lawsuit, without losing the opportunity to pursue the claim in a separate legal action.