• synonyms


  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.
Show More

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.
Show More

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

British Dictionary definitions for pro-


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

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
Show More

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-

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.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper

pro- in Medicine


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