I got slightly sarcastic in a conversation with H last night.

What you wrote didn't come across as sarcastic at all to me.

he stops me after I said the part about S5 saying "dead". H says "We don't say 'dead', but anyway, continue"... He said "The more we use the word, the more real it becomes".

Wow, is that interesting or what? Does that point to his having too much of a fear of death in him? We all fear death and try to not think about it, and we all need to accept that it's just as real as life, and will happen. But some people have a real phobia about it. Perhaps this was a manifestation of his.

You know I'm on this "commitmentphobia" idea right now, and what it's leading me to is that the push-pulls that happen in our relationships are many times attributable to one person actively acting on fears, their partner knee-jerking responding to that, and a cycle ensues. So, I'm believing more and more that the issue in our relationships are not the topical problems we see outwardly to address, but the root fears that those outward signs indicate. The outward problem is the use of the word "dead", but the real problem is H's fear that makes him wish to avoid using or hearing that word. I'll betcha if you had said "not alive" in lieu of dead, there would still be voiced an objection of some kind. It's not about the word itself, but about what the word means to him and how he feels about that.

But is it realistic to never use the word 'dead'? What do you guys think?

It's part of the English lexicon, it's part of the human experience. What do you think?

I get so defensive, I'm not sure why

I think it's because, as you wrote: "I took his words as an attack just because he feels differently than I do."

So what you're getting involved in is a "who's right, who's wrong" type of conversation, as you try to reason with his differing viewpoint. He thinks he's right, you think you're right, and you're each in your camp explaining your reasons why.

I would have been much better off just saying "I disagree that 'dead' is a completely off-limits word. Sometimes it has it's place in a sentence as long as the conversation isn't morbid, instating fear or violent". That's how I feel.

"Reasoning" doesn't always work. Basically, you have two camps, and arguing (and again, I'm using the word "arguing" not meaning the "angry quarrel" sense of it, but in the sense of "stating your supposition") for your camp only serves to set things up as a debate, which is how it turned out. As I mentioned above, that's not the real issue.