FromMiddle Englishunbilefe,unbileve, equivalent toun- +belief.
unbelief (usuallyuncountable,pluralunbeliefs)
- An absence (or rejection) ofbelief, especiallyreligious belief.
1931,William Faulkner,Sanctuary, Vintage, published1993, page35:On hands and knees he looked at the empty siding and up at the sunfilled sky withunbelief and despair.
2009,Diarmaid MacCulloch,A History of Christianity, Penguin, published2010, page781:Soon Spinoza was regarded as the standard-bearer forunbelief, even though pervading his carefully-worded writings there is a clear notion of a divine spirit inhabiting the world, and a profound sense of wonder and reverence for mystery.