theory

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"theories can incorporate facts and laws and tested hypotheses"
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"a scientific hypothesis that survives experimental testing becomes a scientific theory"
3. a belief that can guide behavior"the architect has a theory that more is less"