kentucky plug

Kentucky plug - verb - The act of using a thumb to fill a hole. Most commonly one's own thumb however, it is not uncommon to plug another's hole with the "Kentucky plug".

*calls 911*
Me: uhhh hello my gun exploded and there's a massive hole
911: alright sir calm down, you are equipped with two Kentucky plugs.
Me: wtf is a Kentucky plug?!?
911: sir, please turn your thumb towards the open hole insert it completely into the hole.
Me: *passes out from blood loss like a normal human*