The phrase "watch for" means to be on the lookout for something or someone. There are several synonyms for this phrase, including "keep an eye out," "be alert," "be vigilant," "look out for," "be attentive," "be mindful," "pay attention," "keep watch," and "be observant." Each of these synonyms indicates the need to be aware and focused, whether it's for potential danger, important information, or a specific event or person. Using these synonyms can add variety and nuance to your language, while still conveying the same essential meaning of being vigilant and attentive.