Synonyms of theory

theory

noun

ˈthē-ə-rē 

as in hypothesis

an idea that is the starting point for making a case or conducting an investigation

set out to prove her theory that people can't really taste any difference between colas, so they buy according to the product's image

Synonyms & Similar Words

• hypothesis
• thesis
• proposition
• premise
• assumption
• suggestion
• guess
• supposition
• theorem
• impression
• proposal
• inference
• hunch
• conjecture
• concept
• speculation
• generalization
• suspicion
• presumption
• notion
• presupposition
• premiss
• conception
• concession
• construct
• abstraction
• surmise
• feeling
• guesswork
• proffer
• inkling

Antonyms & Near Antonyms

• fact
• knowledge
• assurance
• certainty

Synonym Chooser

How does the noun theory differ from other similar words?

The words hypothesis and law are common synonyms of theory. While all three words mean "a formula derived by inference from scientific data that explains a principle operating in nature," theory implies a greater range of evidence and greater likelihood of truth.

the theory of evolution

When would hypothesis be a good substitute for theory?

Although the words hypothesis and theory have much in common, hypothesis implies insufficient evidence to provide more than a tentative explanation.

a hypothesis explaining the extinction of the dinosaurs

When might law be a better fit than theory?

The meanings of law and theory largely overlap; however, law implies a statement of order and relation in nature that has been found to be invariable under the same conditions.

the law of gravitation

Example Sentences

Recent Examples of theory

The Manhattan district attorney’s office contends that there are no double jeopardy issues because neither of Mangione’s cases has gone to trial and because the state and federal prosecutions involve different legal theories. —Preston Fore, Fortune, 16 Sep. 2025

The images could help scientists further develop theories of how matter behaves in the extreme environments around supermassive black holes, which have masses of millions or even billions of suns and are found at the hearts of all large galaxies. —Robert Lea, Space.com, 16 Sep. 2025

The theory would place the duality of human nature quite literally in our hands. —Vann R. Newkirk Ii, The Atlantic, 16 Sep. 2025

But Jewett denied there was any evidence Gladney had outed Bragg, calling that a concoction used to bolster the self-defense theory. —Nate Gartrell, Mercury News, 16 Sep. 2025