look up any word, like yeet:
 
1.
Unable to be defeated; Able to be undefeated; Pre-requisite to being undefeated
Man #1 - "Hey man, did you see GSP fight last night?"

Man #2 - "Yeah dude, that guy is undefeatable right now!"
by Captain Seagrams March 28, 2010
 
2.
a word in Huston Street's dictionary: to lack the ability to fail
"If you're staring straight ahead like you're undefeatable, then you're a Longhorn."
by the54effect July 10, 2008
 
3.
not able to lose at beer pong
Andrea and Sarah are undefeatable at beer pong!!
by Andrea H November 26, 2005