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ratio

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Pronunciation

  • IPA: UK /ˈreɪ.ʃi.əʊ/, US /ˈreɪ.ʃi.oʊ/, /ˈreɪ.ʃoʊ/[1]

Etymology

It is borrowed from Latin ratiō (“reckoning, calculation; reason”),[2][3][4] from ratus, the past participle of rērī (“to reckon, think”),[2][5][3] from the PIE root Proto-Indo-European *re- (“to think, reason, count”).[2] It is a doublet of ration and reason.[3]

Earliest recorded meaning

Reason or rationale, in theological writing: 1636 in the OED, the 1630s in Etymonline,[6][2] while MWU dates the first sense to 1638.[6][2][7]

Semantic evolution

The mathematical sense, the relation between two magnitudes of the same kind, is from 1660.[6][3] Looser comparisons between things that can't be precisely measured are from 1808, and the value of silver against gold in a currency with both from 1879.[6] In the 18th century ratio was also briefly used for a ration.[6][4] In philosophy and law the old sense survives in Latin phrases such as ratio decidendi, the reason for a court's decision.[6][8] Etymonline notes that Latin ratio often translated Greek logos in philosophy, though it lacked the Greek sense “word, speech”.[2]

Timeline

  • 1636 – reason, rationale.[6]
  • 1660 – the mathematical sense.[6][3]
  • 1760 – a ration (obsolete).[6]
  • 1879 – the ratio of gold to silver.[6]
  • 1943 – the verb, to enlarge or reduce in proportion.[6]

Modern meaning

Noun

  1. The relation in size or number between two things, often written as a quotient or proportion.
  2. The relative value of gold and silver in a currency system using both.

Word family

  • ratiometer
  • loss ratio
  • anharmonic ratio
  • aspect ratio
  • compression ratio
  • cross ratio
  • current ratio
  • gear ratio

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 Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  3. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  4. ^ a b Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  5. ^ The American Heritage Dictionary of the English Language (2000), 4th ed., Boston: Houghton Mifflin
  6. ^ a b c d e f g h i j k Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
  7. ^ Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  8. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press