'Water bed' definitions:
Definition of 'water bed'
(from WordNet)
noun
A bed with a mattress made of strong plastic that is filled with water
Definition of 'Water bed'
From: GCIDE
- Water bed \Wa"ter bed`\ A kind of mattress made of, or covered with, waterproof fabric and filled with water, thus providing uniform support to the body lying on it; -- also a bed constructed so as to contain such a mattress. It is used in hospitals for bedridden patients, as well as in some private homes. [1913 Webster +PJC]