THEORY
Ancient usage
The English word theory derives from a technical term in philosophy in Ancient Greek.
As an everyday word, theoria, θεωρία, meant "looking at, viewing, beholding", but in more technical contexts it came to refer to contemplative or speculative understandings of natural things, such as those of natural philosophers, as opposed to more practical ways of knowing things, like that of skilled orators or artisans.[b]
English-speakers have used the word theory since at least the late 16th century.[7]
Modern uses of the word theory derive from the original definition, but have taken on new shades of meaning, still based on the idea of a theory as a thoughtful and rational explanation of the general nature of things.