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

Prosecutors used his testimony to shoot down a defense theory that O'Keefe was injured somewhere else and moved to where his remains were recovered the next morning. —Michael Ruiz, FOXNews.com, 29 Apr. 2025

Another form of the Trump administration directly aligning with the unitary executive theory is its explicit push to relitigate Humphrey's Executor, the 1953 Supreme Court ruling that granted protection to federal workers from political persecution. —Tom Rogers, MSNBC Newsweek, 29 Apr. 2025

Social scientists have long debated a theory known as the lipstick index, which posits that sales of small, affordable luxuries tend to rise during times of economic distress. —Leah Prinzivalli, Allure, 28 Apr. 2025

Evidence could be found in the Everton game to support both theories. —Liam Twomey, New York Times, 27 Apr. 2025