Boos, a common expression of disapproval, can have different synonyms depending on their context and intensity. For instance, hissing, jeering, and catcalling are synonymous with boos but are slightly less aggressive. Booing may be substituted with hissing if people want to express their disapproval without making noise. On the other hand, people can opt to say "thumbs down" or "buzz off" if they want to use a less common synonym for boos. Finally, some people use words such as "boring," "uninteresting," or "unimpressive" to express their disdain for something or someone instead of booing. Ultimately, the perfect synonym for booing depends on the situation and how strong or mild the expression of disapproval is.