From Longman Dictionary of Contemporary Englishreactionre‧ac‧tion /riˈækʃən/ ●●● S2 W2 AWL noun 1 to a situation/event [countable, uncountable]REACT something that you feel or do because of something that has happened or been said → response What was Jeff’s reaction when you told him about the job?reaction to the government’s reaction to the fuel crisisin reaction to something An emergency fund was set up in reaction to the famine.2 → reactions3 to food/drugs [countable]MIMD if you have a reaction to a drug or to something you have eaten, it makes you illreaction to a reaction to the immunizationhave/suffer a reaction She had a severe allergic reaction to the drug.cause/bring on/trigger a reaction Certain foods are more likely than others to cause allergic reactions.4 science [countable, uncountable] a) HCa chemical change that happens when two or more substances are mixed together a chemical reaction in the soil b) HPa physical force that is the result of an equally strong physical force in the opposite direction5 change [singular]REACT a change in people’s attitudes, behaviour, fashions etc that happens because they disapprove of the way in which things were done in the pastreaction against a reaction against the traditional values of the nineteenth century6 against change [uncountable] formalPPPCHANGE YOUR MIND strong and unreasonable opposition to all social and political changes The revolutionary movement was crushed by the forces of reaction. → chain reactionCOLLOCATIONS – Meaning 1: something that you feel or do because of something that has happened or been saidADJECTIVES/NOUN + reactionsomebody’s first/initial/immediate reactionHis first reaction was to laugh.somebody’s gut reaction informal (=what they feel or decide immediately, before thinking)You must trust your gut reactions.somebody’s instinctive reaction (=what they do immediately, before thinking)Often your instinctive reaction is to blame someone else.a natural reactionAnger is a natural reaction if you feel undervalued.a knee-jerk reaction (=an immediate reaction that happens without sensible thinking)Environmentalists have a knee-jerk reaction against any development.an emotional reaction (=showing strong emotion, especially by crying)I was surprised by her emotional reaction to the news.a positive/favourable reaction (=showing that someone agrees or likes something)There has been a positive reaction to the campaign.a negative reaction (=showing that someone disagrees or dislikes something)We are concerned about the negative reaction of some of our customers.mixed reactions (=some positive and some negative reactions)The book met with mixed reactions.a violent/angry reactionThe artists were surprised by the violent reactions to their work.a delayed reaction (=a reaction that comes some time after an event)You’re suffering a delayed reaction to the accident.the public reaction (=what the public think about something that happens)The public reaction was less than encouraging.verbsprovoke/produce/bring a reactionThe decision provoked an angry reaction from the local tourist industry.get a reactionWe didn’t know what kind of reaction we would get.gauge somebody’s reaction (=judge or find out someone’s reaction)He watched Jane’s face, trying to gauge her reaction.judging by somebody’s reactionsJudging by the audience’s reactions, the show will be a great success. THESAURUSreaction someone’s feelings, and how they behave, because of something that has happened or been saidI was stunned by the news, and my initial reaction was anger.What was her reaction, when you told her that you were leaving?response what you say or do when someone says or does something to youThe government’s immediate response was to reject the proposal.The decision was made in response to requests from local residents.We are still waiting to see if there is any response.reception a particular type of reaction to someone’s ideas, work etc – used especially in the following phrasesThe plan received warm reception from conference delegates (=they liked it). The film received a mixed reception and commercially it was not successful (=many people did not like it). The Association of Chief Police Officers gave the idea a cool reception (=they did not like it very much).Alford’s views met with a hostile reception (=people were very disapproving).feedback advice, criticism, praise etc that you give to someone, telling them how well they are workingOur English teacher gave us some feedback on our essays.The feedback we have had from our customers has all been positive.negative feedbackbacklash an angry or violent reaction by a group of people to the actions or decisions of othersThere has been a growing backlash against the government from angry voters.fears of a right-wing backlash COLLOCATIONS – Meaning 3: if you have a reaction to a drug or to something you have eaten, it makes you illadjectivesan allergic reactionIf you develop an allergic reaction to your sunscreen, change it.a bad reactionShe had a bad reaction to the medicine.an adverse reaction formal (=a bad reaction)The patient died after having an adverse reaction to the drug.a severe reactionA severe allergic reaction to the drug has killed five Americans.a slight/mild reactionA spider’s venom usually causes only a slight reaction.verbshave/suffer a reactionPeople who eat these products could have an allergic reaction.cause/bring on/trigger a reaction (=make someone ill)Wheat is one of the foods that are most likely to cause a reaction.
Examples from the Corpusreaction• A reaction to these difficulties may be withdrawal, apathy, or acting out behaviour.• an allergic reaction• Can you tell us about your first reactions to this news?• I wanted to write something thoughtful, not just leap in with my gut reaction.• I was stunned by the news, and my initial reaction was anger.• Environmentalists have a knee-jerk reaction against any sort of development, however "green" it might be.• The revolution was defeated by the forces of reaction.• Culture often determines our reaction to events.• Maria's reaction to the birth of her sister was to demand more attention from her mother.• Carter was merely stunned by the reaction from the East; he was blown over backward by the reaction from the West.• Imagine the reaction if David Owen had appeared at Labour's 1989 conference.• There are three aspects of the reaction to the epidemic in Britain that make me terribly uneasy.• My father was so surprised by this violent reaction that he fell silent.reaction to• Her parents' reaction to the news was surprisingly calm.have/suffer a reaction• Tony Norman, the Sunderland keeper, also withdrew after suffering a reaction to a hand operation.• Sure you are going to have reactions.chemical reaction• Fuel cells, which provide electricity generated by a chemical reaction between hydrogen and oxygen, constitute one part of that research.• In a chemical rocket these molecules are the products of a chemical reaction.• Baking is a science, a chemical reaction that starts in a mixing bowl, and low-fat baking is even more complex.• Applications here focus on using gigabit networks to combine the processing power of multiple supercomputers for climate and chemical reaction modeling.• The total energy given off is thousands of times more than any conceivable chemical reaction could produce.• The movement of trace-elements through the environment A large number of chemical reactions take place when trace metals move through the environment.reaction against• The attitudes of this generation are a reaction against the selfish values of the 1980s.