[if-uh n]

Origin of iffen

1930–35; if + -en, of uncertain origin, perhaps an2 (hence a variant of archaic an if) or in’ (see -ing2), extracted from conjunctional uses of considering, excepting, etc.; cf. gin5
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for iffen

Historical Examples of iffen