explain, elucidate, shed light on, clear up, make clear, clarify up, spell out, expound, illuminate
arrest - seize - capture - detain - catch - nab - collar - grasp - understand - comprehend - discern
To apprehend means either to arrest someone, usually by legal authority, or to understand something clearly. In a legal context, it refers to the act of taking a suspect into custody, often after an investigation or when a crime has been committed. In a mental or intellectual context, it describes the process of grasping the meaning, significance, or nature of an idea, situation, or statement. The word can also carry a slight nuance of anticipation or anxiety about something that might happen, though this use is less common in modern everyday speech.