dreamless sleep, characterized by a slow alpha rhythm of brain waves and no marked physiological changes.
Origin of orthodox sleep
First recorded in 1965–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Sleep characterized by a slow alpha rhythm and the absence of REM.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.