The parent said "religions are always false". There was no need for me to hash through the possible definitions that may lend it credence, it was only necessary for me to provide a single definition which proved it inaccurate. That is why I chose that definition.
Ah, yes. Argument by dictionary. That's an excellent strategy: it allows you to avoid the substance of an argument by focusing instead on specific word-use.
Let's try this instead: no religion has been shown to be true. In fact, no religion has demonstrated a basis by which its truth-claims can be evaluated. Religion has no epistemic footing.
You indicate this yourself when you mentioned, "There are over 4,200 religions in the world." (This ignores the various nuanced schisms that exist in many of those 4,200 religions, but we'll let that slide for the moment.) This number indicates there is no real epistemic foundation on which to build a reliable religion. Basically, it's all just gut-feeling, social mechanisms for control, pareidolia, and a desire to know things that are effectively unknowable (or, without answer because the question is bad, such as, "Why are we here?")
So, yes, I think I can say that all religions are wrong, even if they are right in some details. It'd be like the claim, "The earth is warming." That is a correct statement of fact. However, one can be wrong in stating it: "The earth is warming because Hell is getting closer," would simply be wrong.
Religious statements are effectively without basis. Every religious statement that is not grounded in observation and logic (basically, science) can be summed up thusly: "I believe this thing, but I have no basis to assume this thing is true." Asserting a thing as true without a solid basis in observable reality is worse than being wrong. At best it is misleading. At worst, it papers over ignorance, effectively vetoing reason and inquiry.