The Collaborative International Dictionary of English v.0.48:
Sleep \Sleep\, n. [AS. sl[=ae]p; akin to OFries. sl[=e]p, OS.
sl[=a]p, D. slaap, OHG. sl[=a]f, G. schlaf, Goth. sl[=e]ps.
See Sleep, v. i.]
A natural and healthy, but temporary and periodical,
suspension of the functions of the organs of sense, as well
as of those of the voluntary and rational soul; that state of
the animal in which there is a lessened acuteness of sensory
perception, a confusion of ideas, and a loss of mental
control, followed by a more or less unconscious state. "A man
that waketh of his sleep." --Chaucer.
O sleep, thou ape of death. --Shak.
Note: Sleep is attended by a relaxation of the muscles, and
the absence of voluntary activity for any rational
objects or purpose. The pulse is slower, the
respiratory movements fewer in number but more
profound, and there is less blood in the cerebral
vessels. It is susceptible of greater or less intensity
or completeness in its control of the powers.
Sleep of plants (Bot.), a state of plants, usually at
night, when their leaflets approach each other, and the
flowers close and droop, or are covered by the folded
Syn: Slumber; repose; rest; nap; doze; drowse.