noun
lack of faith, conviction; questioning
Synonyms: agnosticism, ambiguity, apprehension, confusion, demurral, difficulty, diffidence, dilemma, disbelief, discredit, disquiet, distrust, dubiety, dubiousness, faithlessness, faltering, fear, hesitancy, hesitation, incertitude, incredulity, indecision, irresolution, lack of confidence, misgiving, mistrust, perplexity, problem, qualm, quandary, rejection, reluctance, scruple, skepticism, suspense, suspicion, uncertainty, vacillation, wavering
Antonyms: belief, certainty, confidence, dependence, faith, reliance, trust
verb
lack confidence in; question
Synonyms: be apprehensive of, be curious, be dubious, be in a quandary, be puzzled, be uncertain, be undetermined, call in question, challenge, demur, disbelieve, discredit, dispute, distrust, fear, fluctuate, give no credence, harbor suspicion, have qualms, hesitate, imagine, impugn, insinuate, misdoubt, misgive, mistrust, not buy, query, read differently, scruple, shilly-shally, skepticize, smell a rat, surmise, suspect, take dim view of, vacillate, waver, wonder at
Antonyms: be certain, believe, not question, rely, trust