sleep-wake cycle: Meaning and Definition of

sleep'-wake' cy"cle

Pronunciation: (slēp'wāk'), [key]
  1. the species-specific biological pattern of alternating sleep and wakefulness, in humans roughly 8 hours of nocturnal sleep and 16 hours of daytime activity.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.