theorize

Etymology

It is formed from English theory + -ize,^[2][3][4] although Merriam-Webster, Hoad and Dictionary.com derive it from Medieval Latin theōrizāre.^[5][6][7] The OED, revising the entry, only compares this Latin verb, recorded in a British source of the 9th century with the meaning "to engage in speculation, contemplate".^[2] Theory is from Late Latin theōria, from Ancient Greek θεωρία (theōría, “contemplation, spectacle”), from θεωρός (theōrós, “spectator”).^[8][4][6]

Earliest recorded meaning

To contemplate or survey, a transitive sense: 1599, in Pil to Purge Melancholie.^[2] The OED's date comes from its 2015 revision, and the other dictionaries place the word later: Etymonline in the 1630s, Dictionary.com in 1630–40, Merriam-Webster in 1638 and the Shorter Oxford in the mid-17th century.^[4][7][5][3]

Semantic evolution

The first sense, which keeps the idea of looking in Greek theōría, was rare and died out by 1638.^[2][8] From 1644 the verb meant to construct a theory about something.^[2] Since 1734 it has also been used without an object, to construct theories.^[2] In 1702 it appears with the sense of bringing something into or out of a state by theories.^[2] Since 1820 it has also meant to suppose or assert as a theory, with a simple object or a clause.^[2] Merriam-Webster also lists forming opinions solely by theory, and the Shorter Oxford indulging in theories.^[5][3]

Timeline

• 1599 – to contemplate, survey (obsolete by 1638).^[2]
• 1644 – to construct a theory of or about something.^[2]
• 1702 – to bring into or out of a condition by theories.^[2]
• 1734 – intransitive, to construct or develop theories.^[2] Merriam-Webster dates the intransitive to 1638.^[5]
• 1820 – to suppose or assert as a theory.^[2]

Meanings

Verb

1. To form a theory or theories; to speculate: Historians have long theorized about the fall of the city.^[5][9][2]
2. To construct a theory about something.^[5][2][3]
3. To suppose or postulate as a theory.^[5][2]
4. (obsolete, 1599–1638) To contemplate, to survey.^[2][3]

Word family

• theorization
• theorizer
• overtheorize

Related words

• theory
• theorist
• theoretical
• theater

Usage notes

The spelling theorise is British.^[5][9]

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
5. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
6. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
7. ^ a b Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
8. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b Collins English Dictionary (2023), Glasgow: HarperCollins