Quantcast
Merriam-Webster Logo
  • Dictionary
  • Thesaurus
  • Scrabble
  • Spanish Central
  • Learner's Dictionary
1

reflex

play
noun re·flex \ˈrē-ˌfleks\

Simple Definition of reflex

  • : an action or movement of the body that happens automatically as a reaction to something

  • : something that you do without thinking as a reaction to something

  • reflexes : the natural ability to react quickly

Source: Merriam-Webster's Learner's Dictionary

Full Definition of reflex

  1. 1 a archaic :  reflected heat, light, or color b :  a mirrored image c :  a copy exact in essential or peculiar features

  2. 2 a :  an automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to a nerve center and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness — compare habit 7 b :  the process that culminates in a reflex and comprises reception, transmission, and reaction —called also reflex action c plural :  the power of acting or responding with adequate speed d :  a way of thinking or behaving

  3. 3 :  a linguistic element (as a word or sound) or system (as writing) that is derived from a prior and especially an older element or system <boat is the reflex of Old English bāt>

Examples of reflex in a sentence

  1. reflexes such as swallowing and blinking

  2. Disagreeing with my suggestions has become almost a reflex for him.

  3. an athlete with great reflexes

  4. My reflexes are slower now that I'm older.



Origin and Etymology of reflex

Latin reflexus, past participle of reflectere to reflect


First Known Use: 1508


2

reflex

adjective re·flex

Definition of reflex

  1. 1 :  directed back on the mind or its operations :  introspective

  2. 2 :  reflexed

  3. 3 :  produced or carried out in reaction, resistance, or return

  4. 4 of an angle :  being between 180° and 360°

  5. 5 :  of, relating to, or produced by a reflex without intervention of consciousness

reflexly

adverb


Origin and Etymology of reflex

Latin reflexus


First Known Use: 1649


REFLEX Defined for Kids

reflex

play
noun re·flex \ˈrē-ˌfleks\

Definition of reflex for Students

  1. 1 :  an action or movement that is made automatically without thinking as a reaction to a stimulus

  2. 2 reflexes plural :  the natural ability to react quickly <A driver needs good reflexes.>




Medical Dictionary

1

reflex

play
noun re·flex \ˈrē-ˌfleks\

Medical Definition of reflex

  1. 1a:  reflected heat, light, or colorb:  a mirrored image

  2. 2a:  an automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to the spinal cord and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness and often without passing to the brain <the knee-jerk reflex>b:  the process that culminates in a reflex and comprises reception, transmission, and reactioncreflexes plural :  the power of acting or responding with adequate speed




2

reflex

adjective re·flex

Medical Definition of reflex

  1. 1:  bent, turned, or directed back :  reflected

  2. 2:  of, relating to, or produced by a reflex without intervention of consciousness




Learn More about reflex


Seen and Heard

What made you want to look up reflex? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

a representation of something

Get Word of the Day daily email!

WORD GAMES

Take a 3-minute break and test your skills!

confounded-person

Which is a synonym of indolent?

melancholy frenetic lazy philistine
Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ