[ pri-kur-ser, pree-kur- ]
/ prɪˈkɜr sər, ˈpri kɜr- /


a person or thing that precedes, as in a job, a method, etc.; predecessor.
a person, animal, or thing that goes before and indicates the approach of someone or something else; harbinger: The first robin is a precursor of spring.
Chemistry, Biochemistry. a chemical that is transformed into another compound, as in the course of a chemical reaction, and therefore precedes that compound in the synthetic pathway: Cholesterol is a precursor of testosterone.
Biology. a cell or tissue that gives rise to a variant, specialized, or more mature form.

Nearby words

  1. precostal anastomosis,
  2. precrime,
  3. precritical,
  4. precuneus,
  5. precursive,
  6. precursory,
  7. precursory cartilage,
  8. precut,
  9. precycle,
  10. pred.

Origin of precursor

1375–1425; late Middle English < Latin praecursor forerunner. See pre-, cursor Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for precursor

British Dictionary definitions for precursor


/ (prɪˈkɜːsə) /


a person or thing that precedes and shows or announces someone or something to come; harbinger
a predecessor or forerunner
a chemical substance that gives rise to another more important substance

Word Origin for precursor

C16: from Latin praecursor one who runs in front, from praecurrere, from prae in front + currere to run

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

Medicine definitions for precursor


[ prĭ-kûrsər, prēkûr′sər ]


One that precedes and indicates something to come.
One that precedes another; a forerunner or predecessor.
A biochemical substance, such as an intermediate compound in a chain of enzymatic reactions, that gives rise to a more stable or definitive product.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.