Word family noun theorist theory theorem theoretician adjective theoretical verb theorize adverb theoretically
From Longman Dictionary of Contemporary Englishtheorytheo‧ry /ˈθɪəri $ ˈθiːəri/ ●●● S2 W1 AWL noun (plural theories) 1 [countable]HPIDEA an idea or set of ideas that is intended to explain something about life or the world, especially an idea that has not yet been proved to be true → theoreticaltheory about/on different theories about how the brain workstheory of Darwin’s theory of evolutiontheory that the theory that light is made up of waves2 [uncountable]HIDEA general principles and ideas about a subject Freudian theory has had a great influence on psychology.political/economic/literary etc theory I’m taking a course on political theory.3 → in theory4 [countable]IDEA an idea or opinion that someone thinks is true but for which they have no prooftheory that Detectives are working on a theory that he knew his murderer.COLLOCATIONSverbscome up with/develop a theoryThese birds helped Darwin develop his theory of natural selection. test a theoryResearchers gave workers a questionnaire to test that theory.prove a theoryNo evidence emerged to prove either theory.support a theoryModern research strongly supports this theory.disprove a theory (also refute a theory formal) (=show that it is wrong)Later experiments seemed to disprove the theory.discredit a theory (=make people stop believing in it)These latest findings discredit his entire theory.ADJECTIVES/NOUN + theorya scientific theoryScientific theories can be tested experimentally.an economic theoryHis economic theory assumes that both labour and capital are perfectly mobile.a conspiracy theory (=a theory that an event was the result of secret plan made by two or more people) A variety of conspiracy theories question the official account of President Kennedy’s assassination.a pet theory (=a personal theory that you strongly believe)Each of them had his pet theory on what had caused the uprising.phrasesthe theory of evolution/relativity etcAccording to the theory of relativity, nothing can travel faster than light. Examples from the Corpus
theory• There's a theory that Kennedy was killed by the CIA.• music theory• It's my theory that the murderer knew his victim quite well.• A hypothesis should be related to a body of theory.• There have been a lot of theories about the meaning of dreams.• This is so: but the take-off theory over-simplifies the real process.• Atkin taught political theory at Hunter College.• Darwin's Theory of Evolution• Einstein's theory of relativity• Several theories of planetary formation include the possibility of disturbance to axial spins during the late stages of formation of a planet.• For it is very difficult to specify just how falsifiable a single theory is.• That Leeds was working within the constraints of this theory as early as 1912 is often overlooked.• This theory helps to explain how animals communicate with each other.theory that• Whether they all cancel out to give a theory that is finite without any infinite subtractions is not yet known.• I have a theory that it only rains when I wash my car.• Only a theory that is completely certain should be allowed to undermine this moral sense.• It takes a special strength of character to spend decades doggedly pursuing a theory that attracts harsh opposition.• The high core temperatures could also be used to support a theory that became fashionable among geophysicists during the l980s.• We don't yet have a complete and consistent theory that combines quantum mechanics and gravity.• New evidence supports the theory that the dinosaurs were wiped out by an asteroid.• We go along with the theory that younger listeners will identify themselves with the group Cancer.• The theory that had wrongly been supposed is that boiling water is hot enough to make tea.• Nevertheless, there can be low-energy predictions of the grand unified theories that might be testable in the laboratory.political/economic/literary etc theory• At this point, economists and economic theory have entered the game.• The ultimate determinants of real investment, whether by foreign or domestic firms, remain a contentious issue in economic theory.• Our basic conceptions of political theory are against this approach.• This tension between economic arithmetic and the prescriptions of economic theory shows up in the discussion that follows.• Despite what standard economic theory tells us about the impact of this proposition, the temptation to support it is great.• Therefore, he devoted more of his time to philosophy and to educating Mexander the Great than he did to economic theory.• Everyone knows that, or at least everyone who has read his or her beginner's guide to literary theory.theory that• Whether they all cancel out to give a theory that is finite without any infinite subtractions is not yet known.• Only a theory that is completely certain should be allowed to undermine this moral sense.• It takes a special strength of character to spend decades doggedly pursuing a theory that attracts harsh opposition.• The high core temperatures could also be used to support a theory that became fashionable among geophysicists during the l980s.• We don't yet have a complete and consistent theory that combines quantum mechanics and gravity.• We go along with the theory that younger listeners will identify themselves with the group Cancer.• The theory that had wrongly been supposed is that boiling water is hot enough to make tea.• Nevertheless, there can be low-energy predictions of the grand unified theories that might be testable in the laboratory.From Longman Business Dictionarytheorytheo‧ry /ˈθɪəriˈθiːəri/ noun (plural theories)1[countable] an idea or set of ideas that is intended to explain why something happens or how it workstheory ofThe book is called ‘An Evolutionary Theory of Economic Change’.The theory is that a healthy employee is cheaper and more productive.2[uncountable] the general principles or ideas of a subjectThey found that theory and practice are two different things (=things do not always happen according to the theory). → content theory → economic theory → Elliott wave theory → employment theory → game theory → monetary theory → price theory → queuing theory → see also Cost of Production Theory of ValueOrigin theory (1500-1600) Late Latin theoria, from Greek, from theorein “to look at” 