that’s a tough question.
Yes…
Anyone who’s actively learning to unicycle, but can’t ride 50 feet yet. The term ‘unicyclist’ is much harder to define.
allright i’ll change the title to “the definition of a unicyclist”
aaahh how do i change the title?
Black magic…
It’s some who is bored of bike riding, skateboarding, inline skating, etc and wants to try a more challenging sport. So they take up unicycling and are willing to push their perseverance and skills to their fullest while at the same time, enjoy the thrills and fun of riding on 1 wheel. 
One who has it in her to ride a Coker?
Yeah, but they start with a DX, KH or Nimbus ISIS. 
And then they just can’t stop!
…one who posts unicycling threads in the wrong forum.
Try Rec.Sport.Unicycling next time. That’s where you talk unicycles. Here’s where you talk about other things.
Thanks! 
It’s someone who put their balls in their pants and rides like there is no tomorrow on the 1 wheel wonder machine.
I like to think of myself as a big inner unicyclist.
i like to also
I think my short definition of a beginner unicyclist would be someone who is still learning the basics.
Uh, don’t ask me to explain exactly what the basics are, but I’ll go so far as to say it depends on what area of unicylcing the person wants to become proficient. Someone can be a world champion of Freestyle and a beginner-level Trials rider, for instance. But I wouldn’t call them a beginner.
Someone who can ride forward, backward and idle can still be a beginner as well though.