Meaning of THEORY in English

noun (plural -ries) Etymology: Late Latin theoria, from Greek theōria, from theōrein Date: 1592 the analysis of a set of facts in their relation to one another, abstract thought ; speculation , the general or abstract principles of a body of fact, a science, or an art , 4. a belief, policy, or procedure proposed or followed as the basis of action , an ideal or hypothetical set of facts, principles, or circumstances, a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena , 6. a hypothesis assumed for the sake of argument or investigation, an unproved assumption ; conjecture , a body of theorems presenting a concise systematic view of a subject , see: hypothesis

Merriam Webster. Explanatory English dictionary Merriam Webster.      Толковый словарь английского языка Мерриам-Уэбстер.