precursor

noun

pre·​cur·​sor pri-ˈkər-sər How to pronounce precursor (audio) ˈprē-ˌkər- How to pronounce precursor (audio)
1
a
: one that precedes and indicates the approach of another
2
: a substance, cell, or cellular component from which another substance, cell, or cellular component is formed
precursory
pri-ˈkərs-rē How to pronounce precursor (audio)
-ˈkər-sə-
adjective

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Precursor Has Latin Roots

With its prefix pre-, meaning "before", a precursor is literally a "forerunner", and in fact forerunner first appeared as the translation of the Latin praecursor. But the two words function a little differently today. A forerunner may simply come before another thing, but a precursor generally paves the way for something. So, for example, the Office of Strategic Services in World War II was the immediate precursor of today's Central Intelligence Agency, while the blues music of the 1930s and 1940s was only one of the precursors of the rock and roll of today.

Choose the Right Synonym for precursor

forerunner, precursor, harbinger, herald mean one that goes before or announces the coming of another.

forerunner is applicable to anything that serves as a sign or presage.

the blockade was the forerunner of war

precursor applies to a person or thing paving the way for the success or accomplishment of another.

18th century poets like Burns were precursors of the Romantics

harbinger and herald both apply, chiefly figuratively, to one that proclaims or announces the coming or arrival of a notable event.

their early victory was the harbinger of a winning season
the herald of a new age in medicine

Examples of precursor in a Sentence

18th-century lyric poets like Robert Burns were precursors of the Romantics a precursor of the modern eggplant
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Li said Sunday that the parties had brokered a preliminary framework for a trade truce including new provisions regarding China’s export controls and safeguards against the smuggling of fentanyl and its chemical precursors. Kate Nishimura, Sourcing Journal, 27 Oct. 2025 The team’s innovation focuses on Surface Immobilized Electrides, a new type of material made by attaching solvated electron precursors to stable surfaces like diamond and silicon carbide. Aamir Khollam, Interesting Engineering, 27 Oct. 2025 This monster is the precursor to slasher villains like Michael Myers and Jason Voorhees, who lumber along on their killing sprees, though this blueprint is far more sympathetic. Steven Thrash, Entertainment Weekly, 24 Oct. 2025 This is a great moment to get the one big Academy Award contender from the first half of the year back in conversation just as the precursor awards voting organizations are getting back together. Joe Reid, Vulture, 24 Oct. 2025 See All Example Sentences for precursor

Word History

Etymology

Middle English precursoure, from Latin praecursor, from praecurrere to run before, from prae- pre- + currere to run — more at current entry 1

First Known Use

15th century, in the meaning defined at sense 1a

Time Traveler
The first known use of precursor was in the 15th century

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Cite this Entry

“Precursor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/precursor. Accessed 29 Oct. 2025.

Kids Definition

precursor

noun
pre·​cur·​sor pri-ˈkər-sər How to pronounce precursor (audio) ˈprē-ˌkər- How to pronounce precursor (audio)
1
2
: a substance or cell from which another substance or cell is formed

Medical Definition

precursor

noun
pre·​cur·​sor pri-ˈkər-sər How to pronounce precursor (audio) ˈprē-ˌ How to pronounce precursor (audio)
1
: one that precedes and indicates the onset of another
angina may be the precursor of a second infarction
2
: a substance, cell, or cellular component from which another substance, cell, or cellular component is formed especially by natural processes

More from Merriam-Webster on precursor

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