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

This theory of form contains a paradox in practice. —Lauren Michele Jackson, New Yorker, 10 May 2025

The murder maestro’s widow, Jill Tuck (Betsy Russell), figures prominently in this installment, with FBI Agent Strahm (Patterson) pursuing a pet theory placing her at the center of the crimes. —Declan Gallagher, EW.com, 10 May 2025

My theory is that Bieber is yearning for the freedom of rappers, especially as a former child star with a ton of people depending on his music not to rock the boat too much so that the money train doesn’t get held up. —Alphonse Pierre, Pitchfork, 9 May 2025

Another component to that theory was Read's broken taillight. —Michael Ruiz, FOXNews.com, 9 May 2025