the act of expressing earnest opposition or protest He even believed he saw visions with his own bodily eyes, and no expostulations of his friends could drive this belief out of his head. — Hoffmann, [..]

1580s, "action of remonstrating in a friendly manner;" 1590s, "argumentative protest," from Latin expostulationem (nominative expostulatio) "a pressing demand, complaint," [..]

reasoning earnestly with a person for purposes of talking them out of something.

(n) the act of expressing earnest opposition or protest(n) an exclamation of protest or remonstrance or reproof

(countable) The act of reasoning earnestly in order to dissuade or remonstrate. (uncountable) A comment of earnest reasoning meant to dissuade or remonstrate.