to be uncertain about; consider questionable or unlikely; hesitate to believe.

to distrust.

Archaic . to fear; be apprehensive about.

to be uncertain about something; be undecided in opinion or belief.

a feeling of uncertainty about the truth, reality, or nature of something.

distrust.

a state of affairs such as to occasion uncertainty.

Obsolete . fear; dread. ?

beyond the shadow of a doubt, with certainty; definitely. Also, beyond a doubt

beyond doubt.

in doubt

in a state of uncertainty or suspense

His appointment to the position is still in doubt.

no doubt

probably.

certainly

There is no doubt an element of truth in what you say.

without doubt

unquestionably; certainly.

noun

belief , certainty , confidence , dependence , faith , reliance , trust , assurance , conviction , credulity , decision

verb

be certain , believe , not question , rely , trust , rely upon

noun

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 , doubtfulness , question , wonder , leeriness , ambivalence , dubiosity , dubitation , miscreance , pyrrhonism , qualification , query , reservation , scruples , worry

verb

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 , question , wonder , apprehension , be undecided , difficulty , hesitation , indecision , misgiving , qualm , skeptical , suspicion , uncertainty , unlikely