Some one who does graffiti, but really sucks at it, so their pieces look like vomit, and they have to write and excuse next to every piece they do because of how bad it is.
Damn you see the kid getting up on the train station the other day?
Yeah, man he sucks, hes a tyro.
Rookie, beginner, n00b.
Man, I was picking up chicks at the dance last night, and John only had 1 number. What a tyro!