[si-dey-shuh n]
noun Medicine/Medical.
  1. the calming of mental excitement or abatement of physiological function, especially by the administration of a drug.
  2. the state so induced.

Origin of sedation

1535–45; < Latin sēdātiōn- (stem of sēdātiō), equivalent to sēdāt(us) (see sedate) + -iōn- -ion
Related formso·ver·se·da·tion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for oversedation


  1. a state of calm or reduced nervous activity
  2. the administration of a sedative
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for oversedation



early 15c., "alleviation of pain;" 1540s, "act of making calm," from Middle French sédation and directly from Latin sedationem (nominative sedatio) "a quieting, assuaging, a calming," noun of action from past participle stem of sedare (see sedate (adj.)).

Online Etymology Dictionary, © 2010 Douglas Harper

oversedation in Medicine


  1. Reduction of anxiety, stress, irritability, or excitement by administration of a sedative agent or drug.
  2. The state or condition induced by a sedative.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.