English Reference
noun

precursor

n.
US /pɹiˈkɝsɝ/ UK /pɹɪkˈɜːsɐ/ pre·cur·sor UK spelling precursor's, precursor's

  1. 01 C1 Advanced Academic

    something that happened or existed before another thing, especially if it influenced the later thing.

    a person or thing that precedes another, often serving as a prototype or an indicator of future developments.

    Simple

    The small local protest was a precursor to the national movement that followed.

    In context

    Historians often view the early 19th-century steam carriage as a direct precursor to the modern automobile, despite its limited commercial success.

    Usage

    Often followed by the preposition 'to'.

  2. 02 C1 Advanced Technical Science

    a chemical substance that is used to make another substance during a reaction.

    a compound that participates in a chemical reaction that produces another compound.

    Simple

    The lab needs a specific precursor to create the new medicine.

    In context

    The synthesis of the polymer requires a highly purified precursor to ensure the final product maintains its structural integrity.

    Usage

    Commonly used in biochemistry and industrial chemistry contexts.

    reactantsource material
    by productend product

The idea is to look for potential exoearths circling other sun-like stars that might have either precursors of life or primitive life.

Phys.org· 24 Aug 2026

Army Air Forces (USAAF), a precursor to the modern Air Force, the Eighth suffered more fatalities than the entire Marine Corps over the course of World War II.

Smithsonian Magazine· 20 Aug 2026

Etymology 1

Inherited from Middle English precursour, from Middle French precurseur or its etymon Latin praecursor (“forerunner”). By surface analysis, precurse + -or.

Etymology 2

From pre- + cursor.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin praecursor<t:forerunner>
Level C1 · Advanced
Frequency Frequent
Updated