precursor

noun

pre·​cur·​sor pri-ˈkər-sər  ˈprē-ˌkər- 

1

a

: one that precedes and indicates the approach of another

b

: predecessor

2

: a substance, cell, or cellular component from which another substance, cell, or cellular component is formed

precursory

pri-ˈkərs-rē 

-ˈkər-sə-

adjective

Did you know?

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.

Synonyms of precursor

• forerunner
• harbinger
• symptom
• herald
• sign
• angel

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

European intelligence sources said Chinese firms were helping Iran rebuild its ballistic missile program, with several shipments of sodium perchlorate – a missile propellant precursor – being delivered from China to Iran since the end of September. —Billy Stockwell, CNN Money, 16 Nov. 2025

Some send precursors to Mexico, legally and illegally. —Mike Brest, The Washington Examiner, 16 Nov. 2025

Tryptophan is an essential amino acid and precursor of melatonin, the sleep hormone. —Marie Bladt, Vogue, 15 Nov. 2025

Its theatrical release coincides with the 80th anniversary of the start of the Nuremberg trials - the first international criminal trials and a precursor to the International Criminal Court. —NPR, 11 Nov. 2025

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

Rhymes for precursor

• bursar
• cursor
• mercer
• purser

Kids Definition

precursor

noun

pre·​cur·​sor pri-ˈkər-sər  ˈprē-ˌkər- 

1

: predecessor

2

: a substance or cell from which another substance or cell is formed

Medical Definition

precursor

noun

pre·​cur·​sor pri-ˈkər-sər  ˈprē-ˌ 

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