misapprehension

This term describes a cognitive error where a person arrives at a false conclusion based on a flawed interpretation of facts. It carries a more formal and polite tone than "mistake" or "misunderstanding," often suggesting a gentle or unintentional error in judgment rather than a blatant failure of intelligence.

Because it refers to a specific state of belief, it is frequently used in legal or professional contexts to describe the basis of a dispute. It implies a gap between the perceived reality and the actual reality, often used in the phrase "under the misapprehension" to describe someone acting upon a false premise.