The act of being a yahoo. Often personified accurately by Truman and his annoying camping tendencies--also could be a Jason camper--as well as his ridiculous classes.
Wow, that guy is yahooistic, yeah i know... Wait, Truman just joined our game on the other team.
The irritatingchat speak of the children of Yahoo chat, aged 9 - ??. They think it's a cool way to talk but really, it just makes them look and sound stupid.
<sumdumchick> - A/S/L! Mi name is Sindi! Wat's Urs?
<sumdude> - LOL. Ur cute, U tell mi B4 I tell U!
<sumdumchick> - Aww! *huggles* Ur a sweet boi! What's Ur name?
(I have to stop before I am sick...you get the idea)
The exuberance a group feel towards any project or policy without having put much thinking, or thought out, the disastrous outcomes such yahoosim brings.
Rick Perry, in calling social security a ponzi scheme and a monstrosity, was playing to the yahooism that was gripping his base who want to end social security.