Synonyms and related words :
Humean, Pyrrhonic, agnostic, cautious, creedless, disbelieving, disinclined to believe, disposed to doubt, distrustful, doubtful, doubting, dubious, faithless, guarded, hard of belief, heretical, hesitant, impervious to persuasion, inconvincible, irreligious, leery, minimifidian, mistrustful, nonbelieving, nullifidian, questioning, quizzical, repudiative, sceptical, shy of belief, skeptic, skeptical, suspecting, suspicious, unbelieving, uncertain, unconfident, unconverted, unconvinced, unconvincible, uncredulous, unpersuadable, unpersuasible, unsatisfied, unwilling to accept, wary, without faith