reaction

[ ree-ak-shuh n ]

/ riˈæk ʃən /

SEE SYNONYMS FOR reaction ON THESAURUS.COM

noun

a reverse movement or tendency; an action in a reverse direction or manner.

movement in the direction of political conservatism or extreme rightism.

action in response to some influence, event, etc.: the nation's reaction to the president's speech.

Physiology. action in response to a stimulus, as of the system or of a nerve, muscle, etc.

Medicine/Medical.

the action caused by the resistance to another action.
a return to the opposite physical condition, as after shock, exhaustion, or chill.

Bacteriology, Immunology. the specific cellular response to foreign matter, as in testing for allergies.

Chemistry. the reciprocal action of chemical agents upon each other; chemical change.

Also called nuclear reaction. Physics. a process in which a nucleus that is bombarded by a photon, particle, or other nucleus, emits a nucleon, alpha particle, or the like, without a significant change in its atomic weight.

Mechanics. the instantaneous response of a system to an applied force, manifested as the exertion of a force equal in magnitude but opposite in direction to the applied force.

Commerce. a decline in the market after an advance in prices.

Origin of reaction

1635–45; re- + action, modeled on react

OTHER WORDS FROM reaction

re·ac·tion·al, adjective re·ac·tion·al·ly, adverb an·ti·re·ac·tion, adjective, noun coun·ter·re·ac·tion, noun

non·re·ac·tion, noun su·per·re·ac·tion, noun

Words nearby reaction

reaching jib, reacquire, react, reactance, reactant, reaction, reaction chamber, reaction engine, reaction formation, reaction of degeneration, reaction time

Example sentences from the Web for reaction

Jundullah and Jaish ul Adl sprang up “in reaction to that kind of oppression,” he said.

The Dangerous Drug-Funded Secret War Between Iran and Pakistan |Umar Farooq |December 29, 2014 |DAILY BEAST
No one likes it when their sandcastle is knocked over, but his reaction is a bit, err, extreme.

Was Baby Jesus A Holy Terror? |Candida Moss |December 21, 2014 |DAILY BEAST
For whatever reason, I grew up watching and loving horror movies—perhaps as a reaction to the environment I was growing up in.

Tim Burton Talks ‘Big Eyes,’ His Taste For the Macabre, and the ‘Beetlejuice’ Sequel |Marlow Stern |December 17, 2014 |DAILY BEAST
JUDNICK: My reaction is so visceral that I immediately, like you, isolate myself so I can breathe.

The Unbearable Whiteness of Protesting |Rawiya Kameir, Judnick Mayard |December 10, 2014 |DAILY BEAST

Ultimately, reflecting other people's reaction was highly effective.

The Right's Rape Trolls vs. Lena Dunham |Emily Shire |December 10, 2014 |DAILY BEAST
Happie cried, crimson with anger and the reaction from her fright.

Six Girls and Bob |Marion Ames Taggart
When the experiment is finished, I first look over the general course of the reaction times.

Collected Papers on Analytical Psychology |C. G. Jung
When the French Revolution broke out, the reaction became, for an interval, in many quarters far stronger still.

The English Church in the Eighteenth Century |Charles J. Abbey and John H. Overton
Then the reaction came, and he hated the very sound of their voices.

For the Term of His Natural Life |Marcus Clarke
I fell beneath a reaction of feelings too powerful for human nature to struggle with.

The Mysteries of London, v. 1/4 |George W. M. Reynolds

British Dictionary definitions for reaction

reaction

/ (rɪˈækʃən) /

noun

a response to some foregoing action or stimulus

the reciprocal action of two things acting together

opposition to change, esp political change, or a desire to return to a former condition or system

a response indicating a person's feelings or emotional attitude

med

any effect produced by the action of a drug, esp an adverse effectCompare side effect
any effect produced by a substance (allergen) to which a person is allergic, the simultaneous equal and opposite force that acts on a body whenever it exerts a force on another body

short for chemical reaction, nuclear reaction

stock exchange a sharp fall in price interrupting a general rise

Derived forms of reaction

reactional, adjective

usage for reaction

Reaction is used to refer both to an instant response ( her reaction was one of amazement) and to a considered response in the form of a statement ( the Minister gave his reaction to the court's decision). Some people think this second use is incorrect

Medical definitions for reaction

reaction

[ rē-ăk′shən ]

n.

A response of an organism or living tissue to a stimulus.

The state resulting from such a response.

A chemical change or transformation in which a substance decomposes, combines with other substances, or interchanges constituents with other substances.

The response of cells or tissues to an antigen, as in a test for immunization.

A pattern of behavior constituting a mental disorder or personality type.

Scientific definitions for reaction

reaction

[ rē-ăk′shən ]

A rearrangement of the atoms or molecules of two or more substances that come into contact with each other, resulting in the formation of one or more new substances. Chemical reactions are caused by electrons of one substance interacting with those of another. The reaction of an acid with a base, for example, results in the creation of a salt and water. Some, but not all, reactions can be reversed.

See nuclear reaction.

An action that results directly from or counteracts another action, especially the change in a body's motion as a result of a force applied to it. Some reactions counteract forces and are not readily apparent. When an object rests on a surface, such as a table, for example, the downward force it applies to the surface is counteracted by an equal but upwards force, or reaction, applied by the surface. See more at Newton's laws of motion.

A response to a stimulus, such as a reflex.

The response of cells or tissues to an antigen, as in a test for immunization.

BROWSE DICTIONARY

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reaction

noun

Origin of reaction

OTHER WORDS FROM reaction

Words nearby reaction

Example sentences from the Web for reaction

British Dictionary definitions for reaction

noun

Derived forms of reaction

usage for reaction

Medical definitions for reaction

n.

Scientific definitions for reaction

BROWSE DICTIONARY

Learning

reaction

noun

Origin of reaction

OTHER WORDS FROM reaction

Words nearby reaction

Words related to reaction

Example sentences from the Web for reaction

(adsbygoogle = window.adsbygoogle || []) .push({}); British Dictionary definitions for reaction

noun

Derived forms of reaction

usage for reaction

Medical definitions for reaction

n.

Scientific definitions for reaction

British Dictionary definitions for reaction