The phrase "zeroed in" is commonly used to describe a situation in which someone has focused or honed in on a particular target or goal. However, there are many synonyms that can be used to convey the same idea. Some examples include: fixated, locked onto, targeted, directed, aimed, concentrated, narrowed down, pinpointed, and honed. Each of these words carries a slightly different connotation, but all suggest a high level of concentration and purposeful action. By using these synonyms in place of "zeroed in," writers and speakers can add variety and nuance to their language while communicating the same essential idea.