Which term describes the formal objection to the sufficiency of another party's pleadings?

The term that describes the formal objection to the sufficiency of another party's pleadings is a demurrer. A demurrer is a procedural tool used in legal contexts to challenge the legal adequacy of the opposing party’s complaint or pleading, essentially arguing that even if all the facts presented in the pleading are true, they do not amount to a legal claim for relief. It focuses solely on the content of the pleadings and does not delve into factual disputes.

In contrast, an objection generally refers to any expression of disapproval or disagreement, often related to evidence during a trial rather than directly addressing the adequacy of pleadings. A motion is a formal request made to the court for an order or ruling, often broader than just addressing pleadings. A counterclaim, on the other hand, is a claim made by a defendant against a plaintiff in response to the original claim, which is not relevant to the formal objection process regarding the sufficiency of pleadings. Thus, the specific legal context and function of a demurrer make it the correct term for this scenario.