It is spelled Lycan, short for Lycanthrope. Lycan refers only to Werewolves, no other were-creatures, because Lycan means Wolf.
You can not become one, you have to be born as one. I could go into further detail, but I think I've gone over this in a thread very similar to this one already. Or maybe it was two threads. Or three. Four. I don't know. Oh well. :)