Uzi is also a family of bolt-action 9mm sub-machine gun, so is not a proper name, and is therefore valid.
But I didn't post to get in a pissing match over playable words, my post was a request for a way to challenge or recind a play.
Well no, thats what wikipedia says, but the game goes by the dictionary. The dictionary states that Uzi is the 1959, trademark name for an Israeli-made submachine gun, developed by Usiel Gal, and manufactured by IMI. Thats why it didn't work, whether people commonly use it in a general sense to classify multiple weapons is irrelevant since it is the actual name of a particular gun. Believe me, I'm not trying to get into a pissing contest about words, because frankly I don't care enough haha, its just a game. I was just pointing out that its not a glitch or error in the game at all, its simply not allowed as part of the rules. You couldn't play Uzi in scrabble either, and wordfeud follows those same rules. I meant no disrespect by it at all, was just trying to clear that up.