High Jinks is a term commonly used to describe boisterous or mischievous behavior. However, there are several synonyms that can be used to describe this type of behavior. For instance, the phrase "monkey business" can be used to describe playful or mischievous behavior. Another synonym for High Jinks is "antics" which refers to childish or amusing behavior. Alternatively, the term "hi-jinx" can be substituted for High Jinks. Additionally, words like "pranks," "shenanigans," and "tomfoolery" all describe mischievous or playful behavior. In conclusion, there are several ways to describe High Jinks or boisterous behavior, and by using synonyms, you can add variety to your language.