sop•o•rif•icPronunciation: (sop"u-rif'ik, sō"pu-), [key]
causing or tending to cause sleep.
pertaining to or characterized by sleep or sleepiness; sleepy; drowsy.
something that causes sleep, as a medicine or drug.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.