The word "repressor" refers to an agent or factor that inhibits or suppresses something. There are several synonyms for this word, including inhibitor, suppressor, controller, restrainer, and moderator. Each of these terms refers to something that limits or regulates something else, whether it be a biological process, an emotional response, or a social behavior. For example, an "inhibitor" is a chemical that slows down or stops a specific biological process, while a "suppressor" is something that decreases the activity of an immune system or gene expression. These synonyms for "repressor" can be used interchangeably in contexts where the restriction or control of something is desired.