theory theory /ˈθiːɝi/

noun

1. () A well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena  ( theory )
   a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena
    Theories can incorporate facts and laws and tested hypotheses
   theories can incorporate facts and laws and tested hypotheses
    True in fact and theory
   true in fact and theory
   
2. () A tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena  ( hypothesis , possibility , theory )
   a tentative insight into the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena
    A scientific hypothesis that survives experimental testing becomes a scientific theory
   a scientific hypothesis that survives experimental testing becomes a scientific theory
    He proposed a fresh theory of alkalis that later was accepted in chemical practices
   he proposed a fresh theory of alkalis that later was accepted in chemical practices
   
3. () A belief that can guide behavior  ( theory )
   a belief that can guide behavior
    The architect has a theory that more is less
   the architect has a theory that more is less
    They killed him on the theory that dead men tell no tales
   they killed him on the theory that dead men tell no tales