IPA: /ˌɛkspəˈstʃʊlətəri/
KK: /ɛkˈspɑːstʃəˌlɛri/
Describing something that expresses strong disagreement or disapproval, often in a formal way.
The teacher gave an expostulatory speech to the students about the importance of honesty.
Expostulatory → It is formed from "ex-" (meaning out of or from) and "postulare" (meaning to demand or claim). The word refers to the act of expressing strong disapproval or objection, often in a formal manner, as if demanding a reconsideration of a situation.
Think of expressing strong disapproval as coming 'out of' ('ex-') a need to 'demand' ('postulare') a change or reconsideration.