So you don't know, or won't say, what our form of government is. Duly noted.
Thanks for playing.
Constitutional Republic (as there are many republics in the world)...emphasis on Constitutional. Look it up.
You are being very pedantic. Here's the Wikipedia definition of Republic:
In American English, the definition of a republic refers specifically to a form of government in which elected individuals represent the citizen body[2] and exercise power according to the rule of law under a constitution, including separation of powers with an elected head of state, referred to as a Constitutional republic[4][5][6][7] or representative democracy. [8]
I speak American English, so when I say "Republic" I mean one with a Constitution.
Many other countries use the term "republic" in their name, but that doesn't make them a republic. For instance, would you consider North Korea a "different kind of Republic" merely because they have the word "republic" in their countries name? I would not, it's a totalitarian dictatorship.
So what legitimate Republics exist which are not Constitutional but some other type? I'm not really aware of any.
So, I still prefer my three-word description to your two-word one, because it's not redundant and calls out the truly unique thing about the USA: the 50 States, which is quite different from all other (true) Republics that I am aware of.
And, while I answered your question (again!), you didn't answer mine. As usual.