noun
rejection, repudiation, renunciation, rebuff, snub, turndown, nonacceptance, denial, disavowal, noncompliance, forbidding, veto, interdiction, proscription, ban, writ, enjoinment, exclusion, discountenancing, disallowance, negation, refutation, renouncement, repulse, withholding, disclaimer, nonconsent, unwillingness, regrets, abnegation, declination, repulsion, reversal, dissent, prohibition, disfavor, disapproval, curb, restraint, thumbs down*; see also opposition 2.
Antonyms consent*, approval, acceptance.