The term 'capture by surprise' can be summarized as trapping someone unexpectedly. The crossword solution for this term is 'TRAP', which is a four-letter word. To TRAP someone means to capture them, usually with the intention of preventing them from escaping. It can be done in a variety of ways, such as using physical restraints or psychological manipulation. Trapping someone by surprise is a tactic often used in warfare, where one side attempts to gain an advantage over the other by catching them off guard.