Gee is slang for the buddy title, guy, as in: "hey guy"
Guy, other than being a name, is just something to call your bro. But guy has gotten a little tired and so we are left with, Gee. Soft G not Hard. as in the Gu sound. Gu-EE.
Antonym: Goo, a goo is a soft bod and deserves little to no respect. Although goo can be a good chirp to throw at your buddies every once and a while.