Etymologically

third

Etymology and origin of the English word third

Confidence
Established
Formation
Inherited
First attested
c. 750 (Cynewulf's Christ)
Inherited from
Old English þridda via Middle English
Ultimate origin
Proto-Indo-European (*trei-)

Pronunciation

  • IPA: UK /θɜːd/, US /θɝːd/[1]

Etymology

It is inherited from Middle English thridde (later therdde), inherited from Old English þridda,[2][3][4] from Proto-Germanic *þriðjaz,[5] from Proto-Indo-European *tri-tyo-, a suffixed form of *trei- (“three”).[2][4] Its relatives include German dritte, Dutch derde, Latin tertius and Ancient Greek τρίτος (trítos).[3][2][5] It is related to three, tertiary and tierce.[6]

Earliest recorded meaning

Next after the second: Old English þridda, about 750, in Cynewulf's Christ.[3]

Semantic evolution

The American Heritage Dictionary explains why three has r before the vowel and third after it: Old English þridda would have given thrid, but the r and i changed places, a change that began in Northumbria in Old English times, as in the form þirdda, and spread south in Middle English.[4] The same swap produced bird from bridd and nostril from thyrl.[4] Etymonline dates the Northumbrian form to about 950 and notes that thrid lasted until the 16th century.[2] The noun “a third part” is from the late 14th century,[2][5] when English also had thirding and thirdendeal,[2] and a musical interval from the 16th century.[5] The third degree (1900, American) comes from the third degree of master mason in Freemasonry (1772).[3] The third rail is from 1890,[2] and the Third World (1963) translates French tiers monde.[3] In the 20th century third often suggested an alternative to a two-sided choice, as in third way.[2]

Timeline

  • c. 750 – Old English þridda (Cynewulf).[3]
  • c. 950 – Northumbrian þirdda.[2]
  • c. 1175 – therdde.[3]
  • late 14th century – noun, a third part.[2]
  • 16th century – a musical interval, and thirdly.[5]
  • 1890 – third rail.[2]
  • 1900 – the third degree.[3]
  • 1963 – Third World.[3]

Modern meaning

Adjective

  1. Coming next after the second in order.
  2. Being one of three equal parts.

Noun

  1. The one next after the second.
  2. One of three equal parts.
  3. (music) An interval of three degrees in a diatonic scale.
  4. The third gear of a vehicle.

Adverb

  1. In the third place; thirdly.

Word family

  • thirdly
  • thirdhand
  • third-class
  • third-rate
  • third-degree
  • third-party
  • petty officer third class
  • third baseman
  • riding
  • third person
  • three
  • thirteen
  • thirty
  • tertiary
  • tierce

References

  1. ^ Jones, Daniel (2011), Cambridge English Pronouncing Dictionary, 18th ed., ed. Peter Roach, Jane Setter and John Esling, Cambridge: Cambridge University Press
  2. ^ a b c d e f g h i j k Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  3. ^ a b c d e f g h i Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  4. ^ a b c d The American Heritage Dictionary of the English Language (2000), 4th ed., Boston: Houghton Mifflin
  5. ^ a b c d e Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  6. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.

Related etymologies

  • fell · also from Old English
  • freedom · also from Old English
  • queen · also from Old English
  • evening · also from Old English
  • therefore · also from Old English
  • hall · also from Old English
  • weather · also from Old English
  • holy · also from Old English
Cite this entry

“Third.” Etymologically, 15 Oct. 2026, etymologically.com/en/third. Accessed 15 Oct. 2026.

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