incredulity
n. US //ˌɪnkɹəˈduɫɪti// UK //ɪnkɹɪdjˈʊlɪti// in·creduli·ty
Attested since 1430. From Middle English incredulite, from Old French incredulité, from Late Latin incredulitas, from Latin incredulus (“unbelieving”) + -itas (“-ity”), equivalent to incredulous + -ity.