A sex act consisting of inserting one's thumb into any orifice of one's sexual partner; loosely inspired by an incident involving the YouTube Channel "Kentucky Ballistics" in which a .50 caliber rifle exploded as he fired it and he had to put his thumb into the injury on his neck to survive.
Hey bro, I gave that girl from the bar the Kentucky Plug last night and she loved it.
A sex position in where the man inserts his thumb into his own buttocks, after which he inserts the thumb into the mouth of woman; commonly done in the doggystyle position.
When it is her time of the month and you stick your thumb in to stop the bleeding while still continuing in a feverish fashion down the dirt road.
Or
A life saving technique used to plug an artery in an emergency situation particularly good during shooting a sketchy custom AK-50 or Slap Rounds
I finally got my hands on Brandon Herrera's AK-50 prototype and it exploded on me. I had to use the Kentucky Plug all the way to the hospital to save my life.