reaction

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.
1. the mutual action of substances undergoing chemical change
2. a process that involves changes within the nucleus of an atom
3. the state resulting from such changes
Med.
1. an action induced by resistance to another action
2. the effect produced by an allergen
3. a depression or exhaustion of energy following nervous tension, overstimulation, etc.
4. an increased activity following depression
Physiol., Psychol. an organic response to a stimulus

re·ac′·tional adjective

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.

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.

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