It’s the room we most often frequent, but good manners dictate that we avoid direct references to the toilet at all costs.
It’s a restroom, a powder room, a washroom, and a loo, which is derived from the French word l’eau for water, as in water closet.
“Seeing a man about a dog” comes from the 1866 play Flying Scud where a character says, “Excuse me Mr. Quail, I can’t stop; I’ve got to see a man about a dog” meaning he needs to leave the room, and fast.
Flying Scud was written by Irish-born playwright Dion Boucicault.