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
• 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

Luckily, a small Vietnamese restaurant on Lexington Avenue became a welcome space for bahn mi and a discussion of the great man theory, the midterm elections, and using AI for gardening advice. — Marisa Meltzer, Vanity Fair, 28 Oct. 2026

In the late eighth century, monkish writers had been thinking about musical theory and experimenting with methods of notation. — Literary Hub, 27 Oct. 2026

Researchers propose theories and typologies of madness and offer advice for health-care professionals. — Sam Kestenbaum, Harpers Magazine, 27 Oct. 2026

Like structuralism, dependency theory viewed the economies of wealthy and poorer countries as closely connected through international trade, with the advantages often flowing disproportionately to the wealthier countries. — Encyclopedia Britannica, 27 Oct. 2026