Origin: Latin suffix -ory
Lavatory has 6 different meanings across 1 category:
a toilet that is cleaned of waste by the flow of water through it
A vessel or fixture for washing
A laver: a washbasin.
Washing, or cleansing by washing.
The word comes from the Latin verb lavare, meaning "to wash," which was used to describe a place for washing. It entered English through Middle English and originally referred to a location where gold could be panned via Spanish influence.