theory

[thee-uh-ree, theer-ee] / ˈθi ə ri, ˈθɪər i /

NOUN

hypothesis, belief

Synonyms

STRONGEST

approach argument assumption code concept doctrine idea ideology method philosophy plan position premise proposal provision rationale scheme speculation suspicion system thesis understanding

STRONG

base basis codification conditions conjecture dogma feeling foundation grounds guess guesswork hunch impression outlook postulate presentiment presumption shot stab supposal supposition surmise theorem

WEAK

formularization suppose systemization

Antonyms

STRONGEST

disbelief fact information reality truth

STRONG

calculation knowledge measurement proof

WEAK

certainty

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

To test the theory, Fang and Si conducted laboratory experiments using a thin layer of water driven by electromagnetic forces.

From Science Daily • Jun. 3, 2026

A reformed set of spending rules kicked into force in 2024, and in theory member states risk fines for violations, though the EU has never gone so far.

From Barron's • Jun. 3, 2026

Casias' disappearance featured prominently in a growing online conspiracy theory earlier this year about the deaths and disappearances of at least 10 people with ties to US scientific research.

From BBC • Jun. 2, 2026

Rick Rubin once said to me — he has a theory about album track lists where he thinks that the first four songs are totally crucial.

From Los Angeles Times • Jun. 1, 2026

There goes Lizzie’s theory that Mum is an American spy.

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

Vocabulary lists containing theory

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