theory
/ˈθɪ.ɹi/noun
theory is spelled T-H-E-O-R-Y: 6 letters and 2 syllables. It appears 76 times per million words in written English, the 1,394th most frequent word form (wordfreq, 2021 data). As a noun, theory means “A description of an event or system that is considered to be accurate” (English Wiktionary, September 2026). The plural of theory is theories.
How many letters and syllables are in theory?
| Letters | 6: T-H-E-O-R-Y |
|---|---|
| Syllables | 2 (from its American pronunciation) |
| In writing | 76 times per million words; the 1,394th most frequent word form |
| Wrong spellings searched | none measured in search |
| Rhymes with |
Sources: letters and syllables from the English Wiktionary's hyphenation or pronunciation and the CMU Pronouncing Dictionary; written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media); rhymes and same-letter words are computed by PlainSpell from its own word list.
How common is theory?
Theory appears 76 times per million words in written English, the 1,394th most frequent word form in the list.
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How do you pronounce theory?
- UK /ˈθɪə.ɹi/
- US /ˈθɪ.ɹi/
- US /ˈθi.ə.ɹi/
Theory has 2 syllables (counted from its American pronunciation in the CMU Pronouncing Dictionary).
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Recordings: En-us-theory.ogg, Wikimedia Commons (author and licence on each file's page).
What rhymes with theory?
4 words on PlainSpell end in the same sounds as theory from its last stressed vowel (/ɪɹi/):
Computed by PlainSpell from the pronunciations in the English Wiktionary (dump of September 2, 2026): a rhyme shares every sound from the last stressed vowel to the end; ordered by written frequency (wordfreq 3.1).
Forms of theory
- theories plural
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
What does theory mean?
The meanings the English Wiktionary records, quoted as written there (source below).
noun
- 1
A description of an event or system that is considered to be accurate.
- 2
A coherent statement or set of ideas that explains observed facts or phenomena and correctly predicts new facts or phenomena not previously observed, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc.
In its most proper acceptation, theory means the completed result of philosophical induction from experience.
- 3
The underlying principles or methods of a given technical skill, art etc., as opposed to its practice.
- 4
A field of study attempting to exhaustively describe a particular class of constructs.
Knot theory classifies the mappings of a circle into 3-space.
- 5
A set of axioms together with all statements derivable from them; or, a set of statements which are deductively closed. Equivalently, a formal language plus a set of axioms (from which can then be derived theorems). The statements may be required to all be bound (i.e., to have no free variables).
A theory is consistent if it has a model.
- 6
The standardization and study of fixed sequences of moves, especially in the opening phase of a game.
Near-synonym: joseki
- 7
obsoleteMental conception; reflection, consideration.
- 8
informalA hypothesis or conjecture.
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract).
Theory in Spanish, French, German and Portuguese
In the sense a coherent set of statements attempting to explain observed phenomena:
Source: English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0), through kaikki.org (Wiktextract). Translations are Wiktionary's, by sense; a linked word has its own PlainSpell page.