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pro

Etymology and origin of the English word pro

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English has two words spelled pro: “for, in favor”, from Latin prō, as in pros and cons, and the short form of professional.[1][2][3]

Pronunciation

  • IPA: UK /prəʊ/, US /proʊ/[4]

pro1 in favor

Confidence
Established
Formation
Borrowing
First attested
c. 1400
Borrowed from
Latin pro via Middle English
Ultimate origin
Latin (prō)

Etymology

The word meaning “in favor” is inherited from Middle English pro,[5] borrowed from Latin prō (“for, on behalf of, before, in place of”),[3][1][5] which is related to per and prae and to Latin prior and prīmus;[2] Etymonline takes it to Proto-Indo-European *per- (“forward, in front of”).[3] The adverb is abstracted from pro and contra “for and against”, New Latin prō et contrā.[1][3]

Earliest recorded meaning

A reason or argument in favor: probably about 1400,[1][3] the 15th century in Merriam-Webster;[5] pro and contra is from probably before 1430.[1]

Semantic evolution

Pro and con is short for pro and contra;[3] Johnson (1755) called it “despicable cant”.[6] The adverb, “in favor”, is from 1572,[1] and the preposition, “in favor of, for”, from 1817.[5] The noun also names a person who supports a proposal or argues the affirmative side.[7][2] Many Latin phrases with pro are used in English, such as pro rata (1354 in the OED), pro forma (1573–80) and pro bono publico (before 1726).[8]

Timeline

  • c. 1400 – noun, an argument in favor.[1][3]
  • before 1430 – pro and contra.[1]
  • 1572 – adverb, in favor.[1]
  • 1817 – preposition, in favor of.[5]

Modern meaning

Noun

  1. An argument or consideration in favor of something: the pros and cons.
  2. A person who supports a proposal or takes the affirmative side.

Adverb

  1. In favor; affirmatively: arguments pro and con.

Preposition

  1. In favor of; for.

Word family

  • pro and con

pro2 professional

Confidence
Established
Formation
Clipping
First attested
1866

Etymology

The short word for a professional is a clipping of professional.[1][3][8]

Earliest recorded meaning

A professional, especially in sport: 1866, in the magazine Sporting Life,[1][3][8] and in Merriam-Webster 1856.[5] At Oxford University pro was earlier short for pro-proctor, from 1848.[8]

Semantic evolution

The adjective is attested by 1915 in the golfing pro shop, a shop run by the resident professional at a club,[3] from 1905 in the OED,[8] and as a general adjective from 1932, also in sport.[1][8] Sports writers used proette for a female professional golfer from 1968,[3] and professional was also used of prostitutes.[3] A person very experienced in some activity is an old pro.[7][9]

Timeline

  • 1848 – short for pro-proctor.[8]
  • 1866 – a professional.[1][8]
  • 1905 – pro shop.[8]
  • 1932 – adjective, professional.[1][8]

Modern meaning

Noun

  1. (informal) A professional, especially a professional athlete.
  2. (informal) A person with long experience of something: an old pro.

Adjective

  1. (informal) Professional: pro football.

Word family

  • proette

Usage notes

The prefix pro- has its own entry.[5] PRO is also an abbreviation for public relations officer and, in Britain, the Public Record Office.[10]

References

  1. ^ a b c d e f g h i j k l m n Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
  2. ^ a b c Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
  3. ^ a b c d e f g h i j k l Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
  4. ^ Jones, Daniel (2011), Cambridge English Pronouncing Dictionary, 18th ed., ed. Peter Roach, Jane Setter and John Esling, Cambridge: Cambridge University Press
  5. ^ a b c d e f g Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
  6. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
  7. ^ a b The American Heritage Dictionary of the English Language (1992), 3rd ed., Boston: Houghton Mifflin
  8. ^ a b c d e f g h i j Simpson, J. A.; Weiner, E. S. C., eds. (1989), The Oxford English Dictionary, 2nd ed., Oxford: Clarendon Press
  9. ^ Merriam-Webster's Collegiate Dictionary (2003), 11th ed., Springfield, Mass.: Merriam-Webster
  10. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press

Related etymologies

Cite this entry

“Pro.” Etymologically, 15 Oct. 2026, etymologically.com/en/pro. Accessed 15 Oct. 2026.

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