A Game Where you cuff Your Hand and Your Enemys Hands into One, both Lifting Your Thumbs And say '1,2,3,4, i declare a thumb War!!'(maybe something other) and try to pin the enemys Thumb under yours. You may only use 1 hand. the winner who pins his enemys thumb down for a short time(5-10 seconds) wins the so called war.
Me And austin Had a thumb War last night, i totally owned him.
On urbandictionary, a thumb war consists giving your own definition a thumbs up and giving a rival's definition a thumbs down on a daily basis while said rival does the same for himself. A thumb war is won when one of the contenders forgets to vote and/or gets a life.
I hope the addition of this definition doesn't provoke a thumb war.