REACTION

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 Dictionary entry overview: What does reaction mean? 

• REACTION (noun)
  The noun REACTION has 7 senses:

1. (chemistry) a process in which one or more substances are changed into others

2. an idea evoked by some experience

3. a bodily process occurring due to the effect of some antecedent stimulus or agent

4. (mechanics) the equal and opposite force that is produced when any force is applied to a body

5. a response that reveals a person's feelings or attitude

6. extreme conservatism in political or social matters

7. doing something in opposition to another way of doing it that you don't like

  Familiarity information: REACTION used as a noun is common.

 Dictionary entry details 

• REACTION (noun)

Sense 1

Meaning:

(chemistry) a process in which one or more substances are changed into others

Classified under:

Nouns denoting natural processes

Synonyms:

chemical reaction; reaction

Context example:

there was a chemical reaction of the lime with the ground water

Hypernyms ("reaction" is a kind of...):

chemical action; chemical change; chemical process ((chemistry) any process determined by the atomic and molecular composition and structure of the substances involved)

Domain category:

chemical science; chemistry (the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions)

Hyponyms (each of the following is a kind of "reaction"):

saponification (a chemical reaction in which an ester is heated with an alkali (especially the alkaline hydrolysis of a fat or oil to make soap))

reducing; reduction (any process in which electrons are added to an atom or ion (as by removing oxygen or adding hydrogen); always occurs accompanied by oxidation of the reducing agent)

photochemical reaction (a chemical reaction produced by the action of light)

oxidation-reduction; oxidoreduction; redox (a reversible chemical reaction in which one reaction is an oxidation and the reverse is a reduction)

oxidation; oxidisation; oxidization (the process of oxidizing; the addition of oxygen to a compound with a loss of electrons; always occurs accompanied by reduction)

neutralisation; neutralisation reaction; neutralization; neutralization reaction (a chemical reaction in which an acid and a base interact with the formation of a salt; with strong acids and bases the essential reaction is the combination of hydrogen ions with hydroxyl ions to form water)

hydrolysis (a chemical reaction in which water reacts with a compound to produce other compounds; involves the splitting of a bond and the addition of the hydrogen cation and the hydroxide anion from the water)

exothermic reaction (a chemical reaction accompanied by the evolution of heat)

endothermic reaction (a chemical reaction accompanied by the absorption of heat)

elimination reaction (a chemical reaction in which a molecule decomposes to two different molecules)

double decomposition; double decomposition reaction; metathesis (a chemical reaction between two compounds in which parts of each are interchanged to form two new compounds (AB+CD=AD+CB))

displacement; displacement reaction ((chemistry) a reaction in which an elementary substance displaces and sets free a constituent element from a compound)

chemical decomposition reaction; decomposition; decomposition reaction ((chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance)

chemical equilibrium; equilibrium (a chemical reaction and its reverse proceed at equal rates)

chain reaction (a series of chemical reactions in which the product of one is a reactant in the next)

aldol reaction (a reaction of aldehydes resulting in an aldol)

addition reaction (a chemical reaction in which one molecule is added to another)

Derivation:

react (undergo a chemical reaction; react with another substance under certain conditions)

Sense 2

Meaning:

An idea evoked by some experience

Classified under:

Nouns denoting cognitive processes and contents

Context example:

his reaction to the news was to start planning what to do

Hypernyms ("reaction" is a kind of...):

idea; thought (the content of cognition; the main thing you are thinking about)

Sense 3

Meaning:

A bodily process occurring due to the effect of some antecedent stimulus or agent

Classified under:

Nouns denoting acts or actions

Synonyms:

reaction; response

Context example:

his responses have slowed with age

Hypernyms ("reaction" is a kind of...):

activity; bodily function; bodily process; body process (an organic process that takes place in the body)

Hyponyms (each of the following is a kind of "reaction"):

automatism (any reaction that occurs automatically without conscious thought or reflection (especially the undirected behavior seen in psychomotor epilepsy))

transfusion reaction (reaction of the body to a transfusion of blood that is not compatible with its own blood; an adverse reaction can range from fever and hives to renal failure and shock and death)

answer (a nonverbal reaction)

passage; passing (a bodily reaction of changing from one place or stage to another)

learned reaction; learned response (a reaction that has been acquired by learning)

inborn reflex; innate reflex; instinctive reflex; physiological reaction; reflex; reflex action; reflex response; unconditioned reflex (an automatic instinctive unlearned reaction to a stimulus)

double take (a delayed reaction indicating surprise)

kinesis (a movement that is a response to a stimulus but is not oriented with respect to the source of stimulation)

taxis (a locomotor response toward or away from an external stimulus by a motile (and usually simple) organism)

tropism (an involuntary orienting response; positive or negative reaction to a stimulus source)

immune reaction; immune response; immunologic response (a bodily defense reaction that recognizes an invading substance (an antigen: such as a virus or fungus or bacteria or transplanted organ) and produces antibodies specific against that antigen)

electrical skin response; electrodermal response; Fere phenomenon; galvanic skin response; GSR; psychogalvanic response; Tarchanoff phenomenon (a change in the electrical properties of the skin in response to stress or anxiety; can be measured either by recording the electrical resistance of the skin or by recording weak currents generated by the body)

overreaction (an excessive reaction; a reaction with inappropriate emotional behavior)

rebound (a reaction to a crisis or setback or frustration)

Derivation:

react (show a response or a reaction to something)

Sense 4

Meaning:

(mechanics) the equal and opposite force that is produced when any force is applied to a body

Classified under:

Nouns denoting natural phenomena

Context example:

every action has an equal and opposite reaction

Hypernyms ("reaction" is a kind of...):

force ((physics) the influence that produces a change in a physical quantity)

Domain category:

mechanics (the branch of physics concerned with the motion of bodies in a frame of reference)

Sense 5

Meaning:

A response that reveals a person's feelings or attitude

Classified under:

Nouns denoting natural phenomena

Context example:

John feared his mother's reaction when she saw the broken lamp

Hypernyms ("reaction" is a kind of...):

response (a result)

Derivation:

react (show a response or a reaction to something)

Sense 6

Meaning:

Extreme conservatism in political or social matters

Classified under:

Nouns denoting cognitive processes and contents

Context example:

the forces of reaction carried the election

Hypernyms ("reaction" is a kind of...):

conservatism; conservativism (a political or theological orientation advocating the preservation of the best in society and opposing radical changes)

Derivation:

reactionary (opposed to political or social liberalism or reform)

Sense 7

Meaning:

Doing something in opposition to another way of doing it that you don't like

Classified under:

Nouns denoting acts or actions

Context example:

his style of painting was a reaction against cubism

Hypernyms ("reaction" is a kind of...):

opposition; resistance (the action of opposing something that you disapprove or disagree with)

Hyponyms (each of the following is a kind of "reaction"):

backlash (an adverse reaction to some political or social occurrence)

 Context examples 

It is a reaction activated by solar light.

(Smog-eating graphene composite reduces atmospheric pollution, University of Cambridge)

A semi-quantitative assessment of the intensity of the wheal and flare reaction.

(Allergen Skin Response Intensity, NCI Thesaurus/CDISC)

On Earth, similar compounds are part of chemical reactions that produce amino acids, the building blocks of life.

(New Organic Compounds Found in Enceladus Ice Grains, NASA)

It occurs more frequently on the face and it is often associated with desmoplastic reaction.

(Amelanotic melanoma, NCI Thesaurus)

Describes a series of reactions in which proteins work together to make molecules.

(Mevalonate pathway, NCI Dictionary)

The day had been too long, the day's effort too intense, and he was deep in the throes of the reaction.

(Martin Eden, by Jack London)

We use catalysts in many aspects of everyday life because they generate chemical reactions that would not otherwise be possible.

(Scientists successfully deliver “Trojan horse” catalysts into cancerous tumour cells to destroy them from within, Universities of Granada)

Severe reactions to sesame are common among sesame-allergic children.

(17% of Food-Allergic Children Have Sesame Allergy, National Institutes of Health)

Of those participants who received peanut OIT, 83% passed the peanut challenge without an allergic reaction, while only 4% on placebo OIT did so.

(Few people with peanut allergy tolerate peanut after stopping oral immunotherapy, National Institutes of Health)

We looked at the inflammatory reactions of 20 volunteers at 0, 3 and 6 hours after eating a standardized meal containing 38 percent fat and their responses were completely unique.

(Humans More Unique than Expected When It Comes to Digesting Fatty Meals, U.S. Department of Agriculture)