Closing in refers to the act of approaching or nearing something, and there are a number of synonyms that can be used to convey this sense of movement and proximity. Terms like drawing near, approaching, nearing, advancing, and coming closer can all be used to describe closing in on a target or goal. Other terms that might be useful in this context include converging, homing in, zeroing in, closing in on the finish line, and closing in on the target. By using these different synonyms for closing in, writers can add variety and interest to their descriptions and help readers get a clearer sense of the action and movement taking place.