From WordNet (r) 3.0 (2006) [wn]:
bathroom
n 1: a room (as in a residence) containing a bathtub or shower
and usually a washbasin and toilet [syn: bathroom,
bath]
2: a room or building equipped with one or more toilets [syn:
toilet, lavatory, lav, can, john, privy,
bathroom]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Lavatory \Lav"a*to*ry\, n.; pl. Lavatories. [L. lavatorium:
cf. lavatoire. See Lave to wash, and cf. Laver.]
1. A place for washing.
[1913 Webster]
2. A basin or other vessel for washing in.
[1913 Webster]
3. A wash or lotion for a diseased part.
[1913 Webster]
4. A place where gold is obtained by washing.
[1913 Webster]
5. A room containing one or more sinks for washing, as well
as one or more toilet fixtures; also called bathroom,
toilet, and sometimes commode. Commode and toilet may
refer to a room with only a toilet fixture, but without a
sink.
Syn: toilet, lavatory, can, facility, john, privy, bathroom.
[WordNet 1.5 +PJC]