Commode.
As other people have pointed out in this thread, in the UK/Australia, it can refer to either one. So I still think my thesis that the word is more along the way towards being a tabu word in the US is correct.
I’m not sure there was ever an original tabu word that that all these euphemisms are substituting for. Or another way to put it, it’s euphemisms all the way down.
I don’t really think it is particularly taboo in the US. I think it appears that way to Brits (et al) because they use the word to refer to the room and we don’t—see the thread I linked to.
That’s mostly why it’s becoming tabu, because it only refers to the porcelain thing in the US. But note I say it’s only moving towards being tabu; it hasn’t quite reached that point yet.
“Where’s the little girl’s/little boy’s room?” 
“Where’s the shitter/crapper?” 
“Are you going to the toilet?” - Ms Blankenship, loudly, on Mad Men. 
Depends where you are. While in New Zealand I was surprised by the number of public restrooms and they were easy to find. Just look for the signs that say “Toilet” with an arrow pointing in the correct direction.
I imagine many Americans would say there’s something “dirty” about the sound of the word “toilet,” with its echoes of “soil” and “oil” (and even “bemoil”). Though that’s probably post-hoc rationalizing…
Yep. In my limited research, I haven’t found what the original term for “place to defecate” is. Best guess is “shithole”.
I once wrote a futuristic story in which they used the word “excretorium” for the bathroom.
Ursula K. Leguin in her novel The Dispossessed frankly called the toilet fixture a “shitstool”.
Yep. Toilet paper is what people call it. Bathroom tissue is something some store use.
In Elizabethan times, “jakes” was the slang term, but monarchs had a “Groom of the Stool” to, erm, attend them. At some point “closet” came in, and later “WC”.
If memory serves, even Chaucer used a euphemism, something like ‘that place to which we all go’.
Actually “Jakes”, from “Jack’s”, is only half a step removed from our present-day “John”. The Toilet was a place every “John” or “Jack” eventually had to go.
The Elizabethans, being bawdy Elizabethans, couldn’t help making punning jokes about it. The classical hero Ajax from the Trojan War found himself involved in these as “A-Jax” = “A Jakes” = “A Toilet”
Euphemisms (which clearly go back to ancient times and before) aside, “shitter” has already been mentioned. The OED has a quote from 1386 mentioning a “schetyngpanne”.
Jaques, aka Master What-ye-call’t, is the guy from As You Like It…
I’ve referred to it as defecatorium .
There is “cacatorium”, found in some slang dictionaries, though I can’t recall ever hearing anyone saying it.
On Taskmaster, Greg and Little Alex Horne always refer to it as “loo roll”.
That’s a ridiculous name. I feel like taking a shower, using several rolls in an attempt to dry off, and then posting a picture with wet tissue stuck all over me and several empty rolls in the background with, of course, a scathing post criticizing their crappy “bath tissue”. 
Obvious misuse of the product. It’s not shower tissue, it’s bath tissue. 
How silly of me! Now, I have to wash all this crap off and try again. LOL
Yet, there is toilet water refresh yourself.
But don’t you dare call that roll toilet paper …
Seriously, if anyone would print that I’d buy a roll or two.