Hammy acting is a phrase used to describe over-the-top or exaggerated performance by an actor. There are several synonyms for this term that you can use in your writing. Here are some of them: melodramatic acting, excessive acting, theatrical acting, overacting, exaggerated acting, showy acting, histrionic acting. While these synonyms can be used interchangeably, they all mean the same thing - an overly dramatic or exaggerated performance by an actor. A subtle performance can be more effective than a hammy performance in many cases, so it's important for actors to strike a balance between emotive expression and realism.