As defined by the AK guy, a life-saving thumb that enters your jugular to stop yourself from bleeding out after firing an over-powdered .50 caliber SLAP round which explodes your bolt action Serbu RN-50. This thumb is necessary to saving your life since a fragment of the exploding bolt action rifle has lacerated your jugular, so without your Kentucky Thumb you would've die on the interstate driving to the nearest hospital as your father speeds past triple digits in your Silverado
by Sliding Bandit May 20, 2021

A soreness or pain that you feel in your thumb after playing video games for too long. Originated from the Nintendo NES controllers because the movement pad had sharp edges on it and extended play would jab those edges into your thumb making it sore.
"Dude, I've been playing for hours and man does my thumb hurt. I think this controller gave me numb thumb..."
by m1mic March 26, 2009

by Beautyass February 21, 2019

The state of being while texting in which your brain is the god of spelling and grammar, but your thumb navigates a touchpad like a drunk walrus behind the wheel of a Corvette.
You: "Bro, I was texting Cindy that she took very aesthetic photos, but I spelled "aesthetic" like "assfart". Now she'll never suck my dick."
Me: "Being thumb dumb is the ultimate game-killer."
Me: "Being thumb dumb is the ultimate game-killer."
by Van Guapo April 11, 2015

The stinging or tingling sensation created by making too many quarter-circles or half-circles on a video game controller's d-pad.
With the release of Ultimate Marvel vs. Capcom 3, I've been getting really bad fighter's thumb lately.
by AxelScar November 23, 2011

by FerneemeryRULES! October 15, 2013

by DJ Wicky December 5, 2022
