Dictionary.com
Thesaurus.com
Synonyms

precursor

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

noun

  1. a person or thing that precedes, as in a job, a method, etc.; predecessor.

    Synonyms:
    forerunner

  2. 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.
    Synonyms:
    herald

  3. 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.

  4. Biology. a cell or tissue that gives rise to a variant, specialized, or more mature form.

precursor British  
/ prɪˈkɜːsə /

noun

  1. a person or thing that precedes and shows or announces someone or something to come; harbinger

  2. a predecessor or forerunner

  3. a chemical substance that gives rise to another more important substance

"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

Etymology

Origin of precursor

1375–1425; late Middle English < Latin praecursor forerunner. See pre-, cursor

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Paul Thomas Anderson and “One Battle” have dominated the precursor awards, but Ryan Coogler and “Sinners” have gained momentum in recent weeks.

From Los Angeles Times • Mar. 15, 2026

This happens every now and again - the last actor to pop up at the Oscars without any major precursor recognition was Andrea Riseborough for To Leslie in 2022.

From BBC • Mar. 12, 2026

He adds that identifying these precursor conditions early may allow doctors to treat underlying diseases sooner and potentially prevent cancer from developing.

From Science Daily • Mar. 6, 2026

But this year’s WBC might just be the precursor to something bigger: the Olympics.

From The Wall Street Journal • Mar. 3, 2026

A quick survey of current diseases lets us trace out four stages in the evolution of a specialized human disease from an animal precursor.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.