1. *Sex position* The act of insertion of one's thumb into any sexually stimulating orifice of one's sexual partner during intercourse, similar to a "wet willy".
2. *Personal first aid* The act of inserting ones thumb into a fatal wound to stem the flow of blood long enough to reach medical professionals.
Coined by YouTuber Brandon Herrera for his friend Scott from the popular Gun-centric YouTube channel, "Kentucky Ballistics", where during a video shoot, his rifle exploded, lacerating his jugular and forcing him to stick his thumb into the wound.
Damn, she was getting real squirmy, so I decided to stick her with the Kentucky Plug
He was gushing all over the place and the ambulance was 5 minutes away, so I had to hit him with a good 'ole Kentucky Plug