reaction Definition
re·ac·tion (rē ak′s̸hən)
noun
- a return or opposing action, force, influence, etc.
- a response, as to a stimulus or influence
- a movement back to a former or less advanced condition, stage, etc.; esp., such a movement or tendency in economics or politics; extreme conservatism
- Chem.
- the mutual action of substances undergoing chemical change
- a process that involves changes within the nucleus of an atom
- the state resulting from such changes
- Med.
- an action induced by resistance to another action
- the effect produced by an allergen
- a depression or exhaustion of energy following nervous tension, overstimulation, etc.
- an increased activity following depression
- Physiol., Psychol. an organic response to a stimulus
reaction Related Forms
reaction Synonyms
reaction
n.
An answer
response, reply, rejoinder, reception, receptivity, return, feedback, feeling, opinion, reflection, counteraction, resistance, backlash, attitude, retort, reciprocation, repercussion, effect, reflex; see also answer 1, opinion 1, result.Reactions to stimuli include: contraction, expansion, dilation, constriction, jerk, knee jerk, tropism, heliotropism, phototropism, cognition, shock, exhaustion, stupor, anger, disgust, revulsion, fear, joy, laughter, wonder.
A backward tendency, especially in politics
conservatism, backlash, status quo, rightism, toryism, retrenchment, regression, relapse, retrogression, retreat, withdrawal, backsliding, return to normalcy, return to the good old days; see also conservatism, stability 1.
reaction Usage Examples
Preposition: of
- halogenoalkanes: The reaction of secondary halogenoalkanes with ammonia No current A ' level syllabus is likely to ask you about this.
- amine: This page summarizes the reactions of amines as nucleophiles.
Converse of object
- provoke: GM cats which don't provoke allergic reactions in humans?
- catalyze: The doctor at Northwick Park Hospital said he has no idea what catalyzed the unique reaction that that made them critically ill.
- trigger: This triggers a chain reaction in the cancer cells, which can result in them commiting suicide.
- elicit: This whole alienating situation has been created in order to elicit a true human reaction.
- catalyze: Presence of MS 4A is essential to attain high selectivities, especially in the reactions catalyzed by the aqua complex.
Adjective modifier
- allergic: They may be able to test your horse's nasal fluid for signs of an allergic reaction.
- adverse: However, similar adverse reactions have been noted in 40 % of these patients.
- emotional: Fear is a common emotional reaction that can be classified into two categories: Phobias Anxiety.
- severe: Over 3,500 cases of severe reactions have been documented.
- suspected: This section provides information about reporting suspected adverse drug reactions for healthcare professionals.
- initial: The initial reaction is often to think the worst.
Modifies a noun
kinetics: The analysis of Al based alloys by calorimetry: Quantitative analysis of reactions and reaction kinetics Review paper by M.J. Starink Int.
Noun used with modifier
- polymerase: The measurement relies on a chemical process called the ' polymerase chain reaction ' or PCR.
- knee-jerk: But the response from the alternative crowd wasn't a knee-jerk reaction.
- hypersensitivity: These cells contain the mediators of the immediate hypersensitivity reaction.
- chemical: An enzyme is a highly active protein that accelerates a chemical reaction.
- chain: Controls: Left Click on a molecule to start the chain reaction.
- redox: To understand what is happening here we need to think about redox reactions.
Browse dictionary entries near reaction
- ‹ reactant
- ‹ reactance
- ‹ react
- ‹ reaching
- ‹ reach-me-down
- ‹ reach
- ‹ re-up
- ‹ re-tread
- ‹ re-trace
- ‹ -'re
- reaction engine ›
- reaction formation ›
- reaction time ›
- reactionary ›
- reactivate ›
- reactive ›
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