A yeenee can basically mean anything you want it to mean. You can substitute it for any part of speech where it makes grammatical sense. For example, you can substitute it for an adjective, but not a conjunction. This word originated from the hoods of Chicago and it was often said before they would "kill an opp or a busta".
noun (plural yeens)
1. (furry jargon) a hyena, often used in a similar way to the word "doggo", except "yeen" is a clipping of the original word
2. a nickname for someone whose fursona is a hyena
verb?
1. a contraction of the words "you ain't" or "you ain't even"
Note:
There are many other nicknames for hyenas that have been derived from this word. (e.g.: yeener, yeen bean, yeeb, etc.) They all mean pretty much the same thing, and are interchangeable.
noun (plural yeens)
1. I got to go see some actual yeens at a wildlife education center yesterday. Did you know there are different kinds of yeens?