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.

But Brent Donnelly, president of Spectra Markets, offered a novel theory about what might have driven stocks higher on Monday.

From MarketWatch • Apr. 13, 2026

And that’s what’s called positive-sum theory, which is that as other groups gain, my group gains, right?

From Slate • Apr. 13, 2026

An LLM is trained on the sum of human written knowledge: philosophy, history, science, political theory.

From The Wall Street Journal • Apr. 13, 2026

The falsehoods -- circulating across tech platforms including X, TikTok and Facebook -- have also added fresh fuel to a longstanding conspiracy theory that NASA's 1969 Apollo 11 moon landing was faked.

From Barron's • Apr. 11, 2026

They were left to grapple on their own with a lot of complicated financial theory.

From "The Big Short" by Michael Lewis

Vocabulary lists containing theory

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