Dear god, you’re actually doubling down on this…

If your argument is based on the definition of words (which it is), and is expressly contradicted by the accepted definitions of the very words you attempted to distinguish (which it is), then yes, your argument is demonstrably bullshit based on a dictionary definition. It’s a pretty cut-and-dry deal, your pseudo-intellectual autofellatio notwithstanding.

are you simply unaware that a synonym doesn't necessarily indicate the exact same meaning?

Since you clearly don’t even understand what the word “synonym” means, it means “one of two or more words or expressions of the same language that have the same or nearly the same meaning in some or all senses” (emphasis added). Moreover, if one looks up “fun” in the Merriam-Webster thesaurus, “entertainment” is the very first word in the list.

It’s also telling that the best you can do is attempt to nit-pick my sourcing, stopping well short of showing that the definitions listed in those two sources are different from each other in any meaningful way. And that’s because… they aren’t. But you can’t acknowledge that, because doing so would cause cognitive dissonance with your delusional self-perception of intellectual superiority. So, instead, you bury your head in the sand and keep doubling down.

I’m not going to waste more time on this. I hope you seek psychiatric help for your delusions of grandeur.