Metalanguage to describe expressing an idea in many different ways

Question

I am looking for a term to describe expressing an idea in many different forms yet the meaning remains the same in each rendition.

An example of this:

The Australians, Australians, the Australian people, the people of Australia, Australia's people etc.

All the phrases above virtually express the same thing yet they are all different, lexico-grammatically speaking.

Thus, the term synonym does not work here. I have also come across the idea of periphrasis but that also has a restrictive definition that does not include my example.

Answer 1

They are different 'linguistic forms' pointing to the same referent, so the term 'periphrases' (generated through grammatical transformations) seems the correct one. Instead, Frege used the term 'sense' (german Sinn) to describe cases such as 'disciple of Plato' and 'tutor of Alexander' to refer to Aristotle, intended as 'different ways of presenting itself' (german 'Art von Gegenbenseins'), though one from a cognitive POV would name them 'conceptualizations'.

Answer 2

In translation studies, I encountered the term variation for this phenomenon. It is a pretty generic term with lots of other uses, but I don't know a better one.

For usage of the term see, e.g., the VARTRA (Variation in Translation) corpus.