When you plug the hole with your thumb.
Damn it's bleeding bad give it the Kentucky thumb or Damn she's bleeding bad give her the Kentucky thumb.
When you have an accident and almost die when shooting your .50bmg and have a hole in your neck, or when you use said thumb for unholy purposes
Scott got the Kentucky thumb both ways
the act of putting your thumb into a hole... (especially the ones bleeding a lot)
"boiiii, imma put a kentucky thumb in her butt tonight"
When you drizzle barbecue sauce on your thumb and proceed to finger bang a girls vagina and eat her out after.
I’m totally going to Kentucky thumb Kristine later tonight.
When your girl is on her period so you shove your thumb in her to stop the bleeding.
Brandon: Hey, how's you're girl?
Scott: She's on her period, so I gave her the old Kentucky thumb.
A sex position where the partner male or female forces there thumb into the other persons anal cavity
I used the Kentucky thumb on my wife last night
Sexual act involving one person just jamming a thumb into any hole in their partner
Last night gave his old lady the kentucky thumb.