a combining form used in the names of chemical compounds which are the normal or parent forms of the compound denoted by the base words: l-norepinephrine.

Nearby words

  1. nor,
  2. nor circuit,
  3. nor gate,
  4. nor'easter,
  5. nor'wester,
  6. nor.,
  7. nora,
  8. norad,
  9. noradrenalin,
  10. noradrenaline

Origin of nor-

short for normal Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for nor-


combining form

indicating that a chemical compound is derived from a specified compound by removal of a group or groupsnoradrenaline
indicating that a chemical compound is a normal isomer of a specified compound

Word Origin for nor-

by shortening from normal

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

Medicine definitions for nor-



A precursor compound that differs from its successor by the absence of a radical group, usually methyl:norepinephrine.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.