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
guy 1: dude did you see that video of that squirrel punching that bear in the face!
guy 2: i know that's the ballsiest squirrel I've ever seen!
guy 2: i know that's the ballsiest squirrel I've ever seen!
by jhon lennon November 20, 2010
Ray William Johnson: "That is by far the ballsiest cat I have ever seen! Is 'ballsiest' a word? Balls.. Ballsiest is now a word!"
by xXHeyBobXx November 18, 2010
by RWJrocksursocks November 17, 2010