Definitions

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.

The base fee also protects the customer, in theory, from being overcharged.

From MarketWatch • Jun. 10, 2026

Pedro Pizarro, chief executive of Edison International, later said that a leading theory of the fire’s ignition was that the idle line became energized briefly through induction, sparking the fire.

From Los Angeles Times • Jun. 9, 2026

None of this endangers the mathematical theory of relativity or the empirical science that confirms it.

From Science Daily • Jun. 8, 2026

And the Mitchell wicket went against a theory held by this England regime that a certain style of cricket cannot be successful in the Test arena.

From BBC • Jun. 6, 2026

Unlike the larger earthquakes, where scientists had a single, generally accepted theory about what was happening far below the surface, there were several theories about what caused harmonic tremors.

From "Mountain of Fire" by Rebecca E. F. Barone

Vocabulary lists containing theory

The Vocabulary.com Top 1000

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The SAT: Language of the Test, List 6

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The New SAT: The Language of the Test

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