Definition - What does Scientific Theory mean?
A scientific theory refers to a well established explanation of a certain aspect of the natural world, which is acquired through the use of the scientific method, and thoroughly tested and confirmed by experimentation and observation. The term "theory" in science has a different meaning from the everyday layman's use of the word, which may refer to an idea or hunch.
Safeopedia explains Scientific Theory
In technical or scientific use, the term theory fits into the same category as a principle or a law, and is considered a well established, evidence-based explanation, which accounts for currently known facts, phenomena or historically verified experience. Early in the hypothesis of the scientific method used to explain a theory, the words hypothesis and theory can be interchangeable, but as a theory is supported by more evidence and support data, it may still maintain the label of theory even after it has evolved from mere conjecture to established fact.