Origin: form of yeahas an isolated or emphatic utterance, with p repr. closing of the lips, creating, in effect, an unreleased labial stop (and perh. also lowering the vowel); cf. the parallel use of p in nope
Dictionary of American Slang and Colloquial Expressions by Richard A. Spears.Fourth Edition. Copyright 2007. Published by McGraw Hill.
Cite This Source
Word Origin & History
yep
1891, variant of yes, altered for emphasis, or possibly infl. by nope.