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

That theory was later debunked when a search of area alligator ponds and the stash house she was allegedly held in turned up nothing. —Theresa Braine, New York Daily News, 27 Feb. 2025

Both theories are plausible, but neither fully explains Broccoli’s head-scratching change of heart. —Benjamin Svetkey and Julian Sancton, The Hollywood Reporter, 26 Feb. 2025

Elsewhere at Mark Fast, red lip theory became plum lip theory. —Ranyechi Udemezue, Vogue, 26 Feb. 2025

But actually, Darwin’s theory is based on fitness to survive, which does not always mean big and strong. —Jamie Lang, Variety, 17 Feb. 2025