It's one way accepted in water 40 Spanish; water or uater, still used in Colombia 41. It originates from the word of English watercloset. Mean bathroom, sanitary, toilet, toilet, toilet, toilet, latrine.
Castilianization and apocope of the watercloset English. It may be the same toilet or bathroom.
VATER: HEALTH. TOILET. TOILET. CUP. TOILET.