A formal greeting gesture where one of the greeter's hand is covered or soiled with food or other grimy substances before shaking hands. Greeter with soiled hand must proclaim, "Let me give you a Kentucky Handshake," and then extend hand forward against the opposing greeter's will.
Cheeto-fingers, chocolate chip crumble-hands, or original recipe fried chicken fingerprints.
"Aw man, Marc was chowing down on that bag of chips and gave my new girlfriend a total Kentucky Handshake."
Short-hand for the word floccinaucinihilipilification, meaning the estimation of something as valueless (encountered mainly as an example of one of the longest words in the English language).