I still don't really understand
in the UK: Parliament has unlimited power and people talk quite a bit about formal constitutions being a good model to be followed
it seems a bit sad the attempt to protect the population against government using a formal constitution doesn't seem to work in reality (even when the wording is as clear as day)
Whose definition?
Answer: The Supreme Court decides the definition of things. Its only unconstitutional if the Supreme Court says so.
That's how the USA can get away with... I dunno... the Office of Censorship in 1941. (https://en.wikipedia.org/wiki/Office_of_Censorship). Definitions change, not only due to different members on the Supreme Court, but also due to different circumstances (WW2 meant that the Supreme Court was willing to ignore the obvious incursion into the 1st Amendment, at least temporarily)
EDIT: I always forget that it was actually the Office of War Information that did the Hollywood Censorship thing (https://en.wikipedia.org/wiki/United_States_Office_of_War_In...), rather than the Office of Censorship.
I guess that's the underlying problem
I'm not sure how you fix it really, though not having direct political appointees as top judges might be a good start
(maybe put an LLM in charge of a supreme court? I kid, I kid)
De facto means in fact. Given that the king does no governing no, he is not, in fact, the ruler. You may be looking for de jure, though I question even that.
If he tried, people would say no. If he insisted, he'd get tossed out on his ear.