/ ˈlævətri; NAmE -tɔːri/ noun ( pl. -ies ) ( old-fashioned or formal )
1.
( especially BrE ) a toilet, or a room with a toilet in it :
There's a bathroom and a lavatory upstairs.
2.
( BrE ) a public building or part of a building, with toilets in it :
The nearest public lavatory is at the station.
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WORD ORIGIN
late Middle English : from late Latin lavatorium place for washing, from Latin lavare to wash. The word originally denoted something in which to wash, such as a bath or pool for bathing, later (mid 17th cent.) a room with washing facilities; the current sense dates from the 19th cent.