Pronunciation: (… sleep)
One of the five stages of sleep. During REM sleep, the eyes move rapidly while closed and dreams occur. REM sleep is the lightest stage of sleep, during which a person may wake easily. During several hours of normal sleep, a person will go through several sleep cycles that include REM sleep and the 4 stages of non-REM (light to deep sleep). Also called rapid eye movement sleep.
Source: NCI Dictionary of Cancer Terms2006-10-14 Date last modified: 2008-01-16