"Uzi" is not contained in any Scrabble® dictionary that I can find online. I am assuming that the Scrabble® powers that be are treating it as a proper noun. However, after reading the Wikipedia article on the Uzi, I do not understand why it would be a proper noun. Here is the description from Wikipedia:
The Uzi (Hebrew: עוזי, officially cased as UZI) /ˈuːzi/ (About this soundlisten) is a family of Israeli open-bolt, blowback-operated submachine guns….The first Uzi submachine gun was designed by Major Uziel Gal in the late 1940s.
To summarize, "uzi" is not a brand name, does not refer to a specific gun (it refers to a class of weapons), and does not refer to a specific manufacturer. The name is derived from a specific person, but does not refer to him. Why is this a proper noun?!
I understand that Uzi is often capitalized, but I don't understand why it should be. Furthermore, the official scrabble rules dictate that "words always capitalized" are not permitted. So another way of posing the question is this: is it permissible to write "uzi" (instead of "Uzi")? If not, why not?
Best Answer
Why is Uzi capitalized? It comes from a name, and people haven't frequently used it in lowercase in publication.
First, the name is derived from a person's name. These usually retain their capitalization. For example, we have:
Even though they come in multiple models and forms, the type of weapon retains the capitalization of the name, even if it's not also the name of the manufacturer.
Furthermore, Uzi hasn't generalized to the point of being lowercase, like some other products. For example, we have:
Popularity makes lowercase more likely, but shifts in usage are arbitrary and vary between individual words. For instance, Ferris wheels are well-known, but the name retains the capitalization.
With Uzi, too, the capitalization remains: in a News on the Web Corpus search, among 2226 results for "uzi," virtually all results are "Uzi." Only 31 of the first thousand results were lowercase. So it will be a while before one can build an argument for "Uzi" being a valid Scrabble word.