Synonym of OBJECT

Disobey : fail to obey (rules, a command, or someone in authority).
Challenge : a call to someone to participate in a competitive situation or fight to decide who is superior in terms of ability or strength.
Deny : state that one refuses to admit the truth or existence of.
Disapprove : have or express an unfavourable opinion.
Object : say something to express one's opposition to or disagreement with something.

Synonym of Object is Disapprove