Deem likely is a phrase which means "consider as possible" or "have an opinion that something is probable". Some of the antonyms for deem likely include "doubt," "disbelieve," "deny," "reject," "oppose," and "repudiate." These words denote a lack of belief, agreement, or acceptance of the likelihood of something happening. To doubt means to have a feeling of uncertainty about something. On the other hand, to disbelieve means to refuse to believe something. Similarly, rejecting or repudiating something means to decline, refuse, or refute its possibility. In contrast to deeming something likely, these antonyms express skepticism, disbelief, or outright denial.