reflex

noun
re·​flex | \ˈrē-ˌfleks \

Definition of reflex 

(Entry 1 of 2)

1a archaic : reflected heat, light, or color

b : a mirrored image

c : a copy exact in essential or peculiar features

2a : an automatic and often inborn response to a stimulus that typically involves a nerve impulse passing inward from a receptor to the spinal cord and then passing outward from the spinal cord to an effector (such 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 reaction

called also reflex action

c reflexes plural : the power of acting or responding with adequate speed

d : a way of thinking or behaving

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

reflex

adjective

Definition of reflex (Entry 2 of 2)

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

2 : reflexed

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

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

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

Keep scrolling for more

Other Words from reflex

Adjective

reflexly adverb

Examples of reflex in a Sentence

Noun

reflexes such as swallowing and blinking Disagreeing with my suggestions has become almost a reflex for him. an athlete with great reflexes My reflexes are slower now that I'm older.
See More

Recent Examples on the Web: Noun

Britain requires only the death of the brainstem, which runs between the spinal cord and the rest of the brain, and regulates reflexes and functions such as breathing. The Economist, "When death is not the end," 26 Apr. 2018 The show of solidarity was a reflex for Abdulaziz, who is also an outspoken defender of Saudi political prisoners. Kareem Fahim, chicagotribune.com, "Meet the Saudi women who advocated for the right to drive — and are paying dearly for it," 23 June 2018 If something gets in your eye like eyelid skin flakes or eye crust, blinking is a natural reflex to try to get rid of that debris, Dr. Massaro-Giordano says. Korin Miller, SELF, "10 Symptoms of Blepharitis, a Bizarre Condition That Can Affect Your Eyes," 7 June 2018 Shivering is a reflex of the body to help keep you warm, according to the website KidsHealth.org. The Enquirer, Cincinnati.com, "Will the Ohio River freeze again? Why is the river steaming?," 2 Jan. 2018 Typical Whac-a-Mole is a game of coordination, speed, and reflexes. John Wenz, Popular Mechanics, "Sadistic Engineering Student Makes an Impossible Whac-a-Mole Game," 24 Mar. 2016 When a wild rabbit is in danger, more white matter is needed for faster reflexes and for learning what to be afraid of. Elizabeth Gamillo, Science | AAAS, "Why your pet rabbit is more docile than its wild relative," 25 June 2018 But a driver's ability to monitor a car's progress depends crucially on reflexes built up over years of driving. Timothy B. Lee, Ars Technica, "Why emergency braking systems sometimes hit parked cars and lane dividers," 8 June 2018 Cat like reflexes from the Slovenian saw Handanovic get a big left hand to the effort, in what was pretty much his first touch of the game. SI.com, "AC Milan 0-0 Inter: Nightmare Night for Mauro Icardi Leaves Inter Kicking Themselves in Derby Draw," 4 Apr. 2018

Recent Examples on the Web: Adjective

One reason the finger must stay off the trigger is that the reflex action of the finger to surprise could cause a loaded gun to fire. Christine Cunningham, Alaska Dispatch News, "Gun-safety rules apply in the photo studio too," 18 July 2017 Sauvignon blancs and grüner veltliners are reflex choices and would be fine. David Tanis, New York Times, "My New Favorite Beans," 17 Mar. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'reflex.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of reflex

Noun

1508, in the meaning defined at sense 1a

Adjective

1607, in the meaning defined at sense 1

History and Etymology for reflex

Noun

Latin reflexus, past participle of reflectere to reflect

Adjective

Latin reflexus

Keep scrolling for more

Learn More about reflex

Statistics for reflex

Last Updated

24 Oct 2018

Look-up Popularity

Time Traveler for reflex

The first known use of reflex was in 1508

See more words from the same year

Keep scrolling for more

More Definitions for reflex

reflex

noun

English Language Learners 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

reflex

noun
re·​flex | \ˈrē-ˌfleks \

Kids Definition of reflex

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

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

reflex

noun
re·​flex | \ˈrē-ˌfleks \

Medical Definition of reflex 

(Entry 1 of 2)

1a : reflected heat, light, or color

b : a mirrored image

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 reaction

c reflexes plural : the power of acting or responding with adequate speed

reflex

adjective

Medical Definition of reflex (Entry 2 of 2)

1 : bent, turned, or directed back : reflected

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

Keep scrolling for more

Comments on reflex

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

to express warning or disapproval

Get Word of the Day daily email!

Test Your Vocabulary

Autumn Words of the Day 2018

  • a-top-down-image-of-road-through-an-autumn-forest
  • Which is a synonym of fugacious?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Word Winder's CrossWinder

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

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!