Credulity (kr-dl-t), n.
Etymology: [L. credulitas, fr. credulus: cf. F. cr. See Credulous.]
Readiness of belief; a disposition to believe on slight evidence. That implict credulity is the mark of a feeble mind will not be disputed. Sir W. Hamilton.
Shades of meaning
Fernald has no entry of its own for credulity; he lists it under fanaticism.
Where he writes about it:
Credulity is not distinctively religious, but is a general readiness to believe without sufficient evidence, with a proneness to accept the marvellous. — from fanaticism
Bigotry is narrow, fanaticism is fierce, superstition is ignorant, credulity is weak, intolerance is severe. — from fanaticism
Bigotry, fanaticism, and superstition are perversions of the religious sentiment; credulity and intolerance often accompany skepticism or atheism. — from fanaticism