dyke
A dyke is a lesbian who often has a masculine look about her, though she may not necesarily be butch.  It was, and still is, used as a derogatory word, except within gay circles, where it has been reclaimed and is now used as a descriptive term.
n.: Yeah, I'm a dyke.
adj.:  Wow, she's really dykey.
offensive:  OMG!  She's, like, such a fucking dyke!  That's sooo totally disgusting.  (Often spoken loudly to another blond, pig-tailed, overly hetero friend when a dyke strolls by.)