Webster's Revised Unabridged Dictionary · 1913

Unbelief

Unbelief , noun

[Prefix un- not + belief: compare Anglo-Saxon ungeleáfa.]

1.
The withholding of belief; doubt; incredulity; skepticism.
2.
Disbelief; especially, disbelief of divine revelation, or in a divine providence or scheme of redemption.
Blind unbelief is sure to err, And scan his work in vain. — Cowper