Theory People Noun ˈθɪəri ˈθiːəri Evolution/Relativity Scientific/Economic Tested

• the theory of evolution/relativity
• scientific/economic theory
• the theories were tested on a sample of the population.
• he developed a new theory about the cause of stomach ulcers.

theory

1. a formal set of ideas that is intended to explain why something happens or exists
• SEE ALSO atomic theory
  https://www.oxfordlearnersdictionaries.com/definition/english/atomic-theory
• the theory of evolution/relativity
• scientific/economic theory
• The theories were tested on a sample of the population.
• He developed a new theory about the cause of stomach ulcers.
• theories on human behaviour
• She has written a book explaining the theory behind her art.
• According to the theory of relativity, nothing can travel faster than light.

Extra Examples

• The debate is centred around two conflicting theories.
• Current feminist theory consists of several different trends.
• His comments are just abstract theory and show little understanding of the realities of the situation.
• the dominant strand of postmodern theory
• the existence of a grand unified theory that determines everything in the universe
• Further experiments seemed to confirm this theory.
• He wrote a number of books on political theory.
• It is a theory that cannot be proved or disproved.
• Marx's theories of history raise one or two major questions.
• The theory was first advanced back in the 16th century.
• This is all theory so far…you'll need to back it up with facts.
2. the principles on which a particular subject is based
• the theory and practice of language teaching
• This is your chance to put theory into practice .
• literary theory
3. an opinion or idea that somebody believes is true but that is not proved
• SEE ALSO conspiracy theory
  https://www.oxfordlearnersdictionaries.com/definition/english/conspiracy-theory
• Theories abound (= people have lots of different ideas) about what happened.
• Here's my theory on how the story's going to end.
• I don't subscribe to the theory that all Hollywood audiences want a happy ending.
• Police are working on the theory that the murderer was known to the family.

Extra Examples

• I have this theory that most people prefer being at work to being at home.
• He has a theory about why dogs walk in circles before going to sleep.
• If the theory is correct, any child can be taught to be a musical genius.
• a conspiracy theory about the princess's death
• One of her pet theories is that people who restrict their calorie intake live longer.
• She doesn't agree with the theory that rich people work harder than poor people.
4. used to say that a particular statement is supposed to be true but may in fact be wrong
• In theory, these machines should last for ten years or more.
• That sounds fine in theory, but have you really thought it through?
• ‘Aren’t you supposed to be retired?’ ‘Yes, in theory.’
• In theory, all children get an equal chance at school.

Word Origin

• late 16th cent. (denoting a mental scheme of something to be done): via late Latin from Greek theōria ‘contemplation, speculation’, from theōros ‘spectator’.