Expostulatory is an adjective that refers to the act of expressing strong disapproval or disagreement. When you express your dissent in a firm manner, you are expostulating. Synonyms of expostulatory include admonitory, cautionary, rebuking, chiding, reproaching, scolding, warning, berating, reprimanding, remonstrant, and reproofing. These words have similar connotations to expostulatory and are often used interchangeably. For instance, you may reprimand someone for their behavior, warn them about the potential risks, or caution them about the consequences of their actions. So, if you want to articulate your disapproval, use these synonyms and choose the one that best fits the context you wish to use it in.