An awful rider. A yeehaw is someone who goes around on their piece of shit, ungroomed horse thinking they are the coolest, best equestrian ever.
You are probably a yeehaw if:
1. You wear a troxel.
2. You jump a horse that is not some kind of warmblood, thoroughbred, or quarter horse.
3. You say things like "how are your hunter-jumpers going?" and when the person responds simply "good" you smile and, not prompted, say "Well my eventing is going awesome."
4. When you say something about horses, people laugh. This is not because you are funny. It is because you don't know shit.
5. You wear a plastic helmet (cover optional to maximize tacky factor) that is color coordinated to match your shirt, hideous britches, loose rubber "boots", and gloves. Your horse's saddlepad, fleece pad, browband, and polos also match your outfit.
6. You dont wear a hairnet and your helmet rests on the top of your forehead. If you do wear a hairnet, it is visible on your forehead and surprisingly not holding your hair back.
7. Your legs swing back and forth at the canter and the word "release" means absolutely nothing to you.
8. You go around to A rated jumper shows wondering why very little paints like yours are showing.
9. You say things like "I've jumped three and a half feet." or my personal favorite, "Oh, my horse jumps like 3'4"." That is not a measurement, dumbass. Figure out why the people with the pretty horses say "oh, three foot. or three foot-six."
10. You are in pony club
"Dude, take those red pants and that troxel and throw them in the trash. You are such a fucking yeehaw."