dissent

(law) the difference of one judge's opinion from that of the majority; "he expressed his dissent in a contrary opinion"

a difference of opinion

the act of protesting; a public (often organized) manifestation of dissent

withhold assent; "Several Republicans dissented"

express opposition through action or words; "dissent to the laws of the country"

be of different opinions; "I beg to differ!"; "She disagrees with her husband on many questions"