What is the Latin word for unbelief?

The usual Latin words for “unbelief” are impietās, īnfidēlitās. The right choice depends on the sense; see the distinctions below.

English → Latin

“unbelief” in Latin

impietāsirreverence, ungodliness, impiety īnfidēlitāsunfaithfulness, faithlessness, infidelity

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

unbelief

perhaps dubitandi obstinatio (generally): impietas (in the Christian sense): obstinata incredulitas (Apul.): infidelitas (ecclesiastical, Augustin). By their unbelief, non credendo (e.g., conjurationem nascentem corroborare).

Quick answer

What is the Latin word for unbelief?: The usual Latin words for “unbelief” are impietās, īnfidēlitās. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.