Nouns

(n)dissent(law) the difference of one judge's opinion from that of the majority“he expressed his dissent in a contrary opinion”
(n)dissenta difference of opinion
(n)protest, objection, dissentthe act of protesting; a public (often organized) manifestation of dissent

Verbs

(v)dissentwithhold assent“Several Republicans dissented”
(v)protest, resist, dissentexpress opposition through action or words“dissent to the laws of the country”
(v)disagree, differ, dissent, take issuebe of different opinions“I beg to differ!”, “She disagrees with her husband on many questions”