A sleeve tattoo covers most or all of a person's arm. Do you know anyone with a sleeve?
I use to know someone with a sleeve tattoo. It was entirely Pearl Jam-themed. But I haven't talked to him in years. 
Apparently they also use this term to refer to a large leg tattoo - but I've never personally heard it called that.
A leg sleeve? I've never heard of that either. I've got a few tattoos myself. Someday I'd like a half sleeve, but probably not the whole thing. On my arm, of course, not my leg. 
Yep a leg sleeve LOL!  You could get a quarter sleeve that only covers part of the arm