The word 报案 (bào'àn) is a compound verb formed by combining two meaningful characters: 报 (bào), meaning "to report" or "to notify", and 案 (àn), meaning "case" or "legal matter". It follows a common grammatical structure in Chinese where a verb (报) is paired with its object (案) to create a specific action phrase, literally meaning "to report a case". This construction succinctly conveys the complete concept of formally filing or notifying the authorities (like the police) about an incident, crime, or dispute that requires official attention.