the natural periodic suspension of consciousness that is essential for the physical and mental well-being of higher animals
What hath night to do with sleep? — Milton
a sleeplike state; torpor or inactivity
the state of an animal during hibernation
euphem death
a period spent sleeping
informal dried mucus that sometimes collects in the eye corners when sleeping
go to sleep
to fall asleep
said of a limb: to become numb
put to sleep
to kill (a sick animal) humanely
to make (somebody) unconscious with an anaesthetic
[Old English slæp]