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  1. in favor of a proposition, opinion, etc.
noun, plural pros.
  1. a proponent of an issue; a person who upholds the affirmative in a debate.
  2. an argument, consideration, vote, etc., for something.
Compare con1.

Origin of pro1

1350–1400; Middle English < Latin prō (prep) in favor of, for; akin to per-, Greek pró, Sanskrit pra


  1. professional.
noun, plural pros.
  1. a professional.
  2. the pros, the professional athletic leagues, as of football, baseball, or basketball: He's sure to be signed by the pros.

Origin of pro2

First recorded in 1840–50; shortened form


noun, plural pros. Slang.
  1. prophylactic(def 5).

Origin of pro3

shortened form


[proh; English proh]
preposition Latin.
  1. for.


  1. proline.


or P.R.O.

  1. public relations officer.


  1. a prefix indicating favor for some party, system, idea, etc., without identity with the group (pro-British; pro-Communist; proslavery), having anti- as its opposite.
  2. a prefix of priority in space or time having especially a meaning of advancing or projecting forward or outward, and also used to indicate substitution, attached widely to stems not used as words: provision; prologue; proceed; produce; protract; procathedral; proconsul.

Origin of pro-1

< Latin prō-, pro-, combining form representing prō pro1


  1. a prefix identical in meaning with pro-1, occurring in words borrowed from Greek (prodrome) or formed of Greek (and occasionally Latin) elements.

Origin of pro-2

< Greek, combining form of pró for, before; see pro1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for pro

Contemporary Examples

Historical Examples

  • C4-6 are a reduplication, not unnatural indeed, but pro tanto tautological.



  • “Yes, but not for motion without the ‘pro,’” objected de Spain.

    Nan of Music Mountain

    Frank H. Spearman

  • You will never be happy if the pro and the con distress you alike.

  • Don't you see that with Sawyer on pro there's a big hole in the line?

    Left End Edwards

    Ralph Henry Barbour

  • The Catholics raised the banner "Pro religione et libertate!"

    The Story of Russia

    R. Van Bergen, M.A.

British Dictionary definitions for pro


  1. in favour of a motion, issue, course of action, etcCompare anti
  1. in favour of
noun plural pros
  1. (usually plural) an argument or vote in favour of a proposal or motionSee also pros and cons
  2. (usually plural) a person who votes in favour of a proposal, motion, etc
See con 2

Word Origin

from Latin prō (prep) in favour of


noun plural pros
  1. informal short for professional
  2. slang a prostitute
the internet domain name for
  1. professional practitioner
  1. informal short for professional

Word Origin

C19: by shortening


abbreviation for
  1. Public Records Office
  2. public relations officer


  1. in favour of; supportingpro-Chinese
  2. acting as a substitute forproconsul; pronoun

Word Origin

from Latin prō (adv and prep). In compound words borrowed from Latin, prō- indicates: forward, out (project); forward and down (prostrate); away from a place (prodigal); onward in time or space (proceed); extension outwards (propagate); before in time or place (provide, protect); on behalf of (procure); acting as a substitute for (pronominal); and sometimes intensive force (promiscuous)


  1. before in time or position; anterior; forwardprophase; procephalic; prognathous

Word Origin

from Greek pro (prep) before (in time, position, rank, etc)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for pro


1866, shortening of professional (n.). The adjective is first recorded 1915 (in golfing's pro shop).


"a consideration or argument in favor," c.1400, from Latin pro (see pro-). Pro and con is attested from c.1400, short for pro and contra "for and against" (Latin pro et contra).


word-forming element meaning "forward, forth, toward the front" (e.g. proclaim, proceed); "beforehand, in advance" (prohibit, provide); "taking care of" (procure); "in place of, on behalf of" (proconsul, pronoun); from Latin pro "on behalf of, in place of, before, for, in exchange for, just as," which also was used as a prefix.

Also in some cases from cognate Greek pro "before, in front of, sooner," which also was used in Greek as a prefix (e.g. problem). Both the Latin and Greek words are from PIE *pro- (cf. Sanskrit pra- "before, forward, forth;" Gothic faura "before," Old English fore "before, for, on account of," fram "forward, from;" Old Irish roar "enough"), extended form of root *per- (1) "forward, through" (see per).

The common modern sense "in favor of, favoring" (e.g. pro-independence, pro-fluoridation, pro-Soviet) was not in classical Latin and is attested in English from early 19c.

Online Etymology Dictionary, © 2010 Douglas Harper

pro in Medicine


  1. proline


  1. Earlier; before; prior to:progenitor.
  2. Rudimentary:pronucleus.
  3. Anterior; in front of:procephalic.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.