Actually, an adjective is simply a word used to describe a word, and most nouns can become adjectives the same way verbs can become adverbs. Unless something is hypenated (double-click), or a compound word (rainbow) it is always an adjective + a noun.
In this case we have "weapon". What kind of weapon? A "_melee_ weapon". Same thing as saying you have a "car". What kind of car? A "_red_ car".
That's exactly my point. Almost all nouns are, but melee seems not to be. I even looked it up, though only on the internet, I don't have my big dictionary available right now.
Cheese salad would be the same kind of wording with cheesy being the adjective.
Anyway... it wasn't my intention (yet my fault) to get caught in such a discussion so before it gets out of hand I'll leave it at that.
Besides, there are at least two weapons (the Jupiter Shockclub and the Defiance EX Shocker) that state they're equipped to be used as both a melee weapon and a ranged weapon, and can be used as either without having to "improvise" with them. Makes very little sense to me that you'd lose your ability to defend yourself with the stunner in your off-hand just because you pulled the trigger on the other one.
I think the act of aiming and actually hitting something with a gun differs greatly from its usage as a club. The Defiance EX Shocker, might be a different kind, as its contacts point the same direction as its "barrel", but then again it does exactly the same damage in melee range, as it is a contact weapon.
Well, as I mentioned above, I'll stop derailing this thread.