noun

a feeling of uncertainty or lack of conviction.

some doubt has been cast upon the authenticity of this account

uncertainty,lack of certainty,unsureness,indecision,hesitation,hesitancy,dubiousness,suspicion,confusion,question mark,queries,questions,dubiety,incertitude,diffidence,insecurity,inhibition,unease,uneasiness,apprehension,wavering,vacillation,irresolution,lack of conviction,demurral,scepticism,distrust,mistrust,lack of trust,doubtfulness,cynicism,disbelief,incredulity,unbelief,misbelief,lack of confidence/conviction,wariness,chariness,questioning,reservations,misgivings,suspicions,qualms,leeriness

verb

feel uncertain about.

I doubt my ability to do the job