What word describes organisations like the Federation, Klingon Empire, and Dominion in Star Trek?

There are many territorial areas and governmental bodies in Star Trek:

• The United Federation of Planets


• The Klingon Empire


• The Romulan Empire


• The Ferengi Alliance


• The Dominion

and probably a host of others I'm forgetting about.

So what word do the people in Star Trek use to refer to these groupings? Nation, Federation or Union all seem common but only to refer to specific territorial/governmental bodies. They also seem quite out of place when referring to other bodies (the Klingons aren't a Federation, etc).

I would strongly prefer an in-universe answer, if one exists.