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

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

by Beautyass February 21, 2019

a really annoying commerical on The N that is very over-used and is retarded because you have to pay 10 dollars every month for the stupid thing, just for ringtones. get a music phone and have the same thing for FREE.
OMFG NOT THIS THUMB PLAY COMMERCIAL AGAIN! this commercial is so annoying and makes me want to change the channel. it is over-used.
by ashley;nicole February 29, 2008

A sore and/or numb sensation between the nuckle and base of the thumb caused by hitting the joystick button of a game controller for hours on end. The ailment became common after playing a classic side-scrolling shooter called, "Contra". Sometimes confused with carpal tunnel syndrome.
by RobertMHoehn March 20, 2010

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
