The term 'zeroing in on' can be summarized by the crossword solution 'homing, ' which is a six-letter word. Homing is an instinctive behavior in which an animal or person returns to its home or origin. This behavior is often used metaphorically to describe the process of narrowing down a search or investigation to a specific target. In this context, zeroing in on something means to focus on it and hone in on it until the desired result is achieved.