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

Other Reddit users agreed with the theory and offered their own idea that Gemma may have volunteered her body to Lumon for experimentation. —Jason Pham, StyleCaster, 21 Mar. 2025

As this theory went, an unbalanced government would descend into tyranny with a too-powerful monarch; oligarchy under a dominant aristocratic class; or anarchy with the people out of control. —Carla Gardina Pestana, The Conversation, 20 Mar. 2025

The formation of the death cross could raise warning signals for the Dow Jones Industrial Average and the broader economy, according to Dow theory. —Hakyung Kim, CNBC, 20 Mar. 2025

The findings indicate that this galaxy was already mature in the early universe, challenging theories of galactic evolution. —Robert Lea, Space.com, 20 Mar. 2025