[ adjective, noun ree-fleks; verb ri-fleks ]
/ adjective, noun ˈri flɛks; verb rɪˈflɛks /
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See synonyms for: reflex / reflexes on Thesaurus.com



verb (used with object)



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Origin of reflex

1500–10; <Latin reflexus bent back, past participle of reflectere to reflect
re·flex·ly, adverbre·flex·ness, nounmul·ti·re·flex, nounsem·i·re·flex, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for reflex


noun (ˈriːflɛks)

adjective (ˈriːflɛks)

maths (of an angle) between 180° and 360°
(prenominal) turned, reflected, or bent backwards

verb (rɪˈflɛks)

(tr) to bend, turn, or reflect backwards
reflexible, adjectivereflexibility, noun
C16: from Latin reflexus bent back, from reflectere to reflect
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

Medical definitions for reflex

[ rēflĕks′ ]



Being an involuntary action or response, such as a sneeze, blink, or hiccup.
Bent, turned, or thrown back; reflected.


To cause to undergo a reflex process.
To reflect.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for reflex

[ rēflĕks′ ]

An involuntary physiological response to a stimulus, as the withdrawal of a body part from burning heat.
An unlearned or instinctive response to a stimulus. Also called unconditioned response See more at classical conditioning.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for reflex


An action or movement not controlled by conscious thought. A reflex may be anything from a hiccup to the involuntary response of a body part, such as the action that occurs in the knee-jerk reflex.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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