1 definition by ImmaLetYouFinishBut
An adjective to describe something that takes alot of bravery, or alot of balls. This word is usually used to describe something crazy done by the high kid down the hall.
Friend One: Hey did you hear Mike tried to jump into a pool under the express way?
Friend Two: Yeah, that's the ballsiest thing he's ever done.
Friend Two: Yeah, that's the ballsiest thing he's ever done.
by ImmaLetYouFinishBut November 16, 2010