There's a old joke about this from Jack Parr, told on the Tonight Show:

An English lady, while visiting Germany, was looking for a room to rent. She found a suitable one owned by a local schoolmaster. After returning home, she remembered she hadn’t seen a "W.C." (water closet/bathroom) on the property. She wrote a letter to the schoolmaster asking where the W.C. was located.

The schoolmaster, not knowing much English, was puzzled by the initials "W.C." He took the letter to the parish priest, and together they concluded that the lady must be asking about the local Wayside Chapel.

The schoolmaster wrote the following reply:

Dear Madam,

I take great pleasure in informing you that the W.C. is situated nine miles from the house, in the center of a beautiful grove of pine trees. It is capable of holding 250 people and is open to the public on Sundays and Thursdays.

As a large crowd is expected during the summer months, I advise you to arrive early. This may prove an unfortunate inconvenience to you if you are in the habit of going regularly. Rest assured, however, that there is plenty of standing room.

Many people bring their lunch and make a day of it, while others arrive at the last minute and can only find standing room. A special feature is the organ music, which accompanies all proceedings. The acoustics are excellent, and even the most delicate sounds can be heard by everyone.

It may also interest you to know that my daughter was married in the W.C., as it was there that she met her husband. I can still remember the rush for seats. There were ten people in every seat that day!

My wife is very delicate, so she cannot go regularly. It has been over six months since she last went, which is naturally a great trial for her.

I shall be delighted to reserve the best seat for you, where you can be seen by everyone.

Yours faithfully,

The Schoolmaster

Pronounced like "vayssay" in French because the English double-U is actually a double-V.

Toilet paper can be referred to as "PQ," for "papier cul" (translation of "ass paper").

Another word for toilet is john, which is also a presidential middle name.

Thats why colloquially we call toilets "vécé" in hungarian which is basically VC(wc) pronounced as a word.

The more you drink the more double-you see

In India, WC is the Western Commode, as opposed to the Indian Commode (squat toilet)

I didn't even see this post before I started my "Uncle John's Facts From A Closed Toilet", but consider this my pearls in the alley in front of a Young Bruce.

This always confused the hell out of me in Mexico.

Wash Closet sounds like a small room for washing clothes or a person, however I was previously aware of the term.

If I remember correctly, some Asian countries call it WC. I hope this translates well, because the next part is really dumb.

Imagine if we were all forced to go into a tiny room and swing from clothing hangers while water blasted our buttholes!

Yippee!

And 'crapper' is from Thomas Crapper, who was one lauded as the inventor of the toilet, but that is s bit overblown.

Still the name stuck