Serious question: What is Zionism?

https://alethonews.com/2019/04/01/serious-question-what-is-zionism/
If Zionism was the political movement to establish a homeland for the Jewish people in the Middle East, then surely it achieved its goal and the term ceased to have meaning in terms of defining the objectives of a political movement.
Alternatively, if Zionism then morphed into support for the continued existence of a Jewish state in the Middle East, then the only point of view what would not be Zionist would be the one that calls the Jewish state illegitimate and calls for it to be dismantled. Yet there are few political voices that call for such an approach, and governments that have referred to the Jewish state as illegitimate have been demonized for doing so. Clearly, such a view is regarded as a fringe one.
So, what is Zionism today? Is everybody who does not declare Israel to be an illegitimate state that should be dismantled and the land given back to its dispossessed people a Zionist? Would that not make nearly everyone a Zionist? And, if so, does that not deprive the term of any meaning whatsoever?