The point is that only a conviction of terroism qualifies one as a convicted terrorist. Just like only a conviction of murder qualifies one as a convicted murderer. If someone killed someone else, was convicted of manslaughter, but you personally think it was murder, you might feel justified in calling them a murderer. But it would make no sense for you to call them a "convicted murderer."

At which point, I would say we have successfully deflected off of the word "terrorist" and allowed ourselves to get stuck in in the non-impactful rut of fixating on "convicted".

Which circles back to my original point that the fact-checkers often resort to manipulating language in order to arrive at the verdicts they present. I find this kind of misdirection incredibly dishonest - both intellectually and ethically.

I couldn't really disagree more. Convicted is the key point here. Anyone can throw around the word 'terrorist' to describe someone, but conviction is a concrete fact about the legal system. The people calling this woman a "convicted terrorist" are leaning on the convicted. Without it their claim would feel much less weighty.

e.g. lots of people have called Kyle Rittenhouse a 'terrorist'. Say he had been convicted on one of the charges against him - would it be fair to call him a 'convicted terrorist' just because some people feel he is a terrorist, and he was convicted of something? Clearly not.

"Rosenberg is a convicted criminal who planned terrorist acts" is a far more defensible claim, so why not just say that?

By your definition, no successful suicide bomber would ever be a terrorist, because the dead do not go to trials.

Of course they would, they just wouldn't be a convicted terrorist.

Osama B.L. and I both belong to the same category of "not a convicted terrorist", yet that fact seems quite misleading.

I don't see how it would be misleading. Despite various indictments, AFAIK bin Laden was never convicted of anything. There are many categories you share with him, e.g. "people who didn't live in the seventeenth century" and "people who have never been in my kitchen."

In your view, do adjectives not matter for facticity, only nouns? Could we fairly call Osama bin Laden a Russian terrorist or a female terrorist?