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.

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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

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Etymology

Origin of precursor

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

Explanation

You've heard the old saying "Pride comes before the fall?" Well, you could just as easily say pride is a precursor to the fall. A precursor is something that happens before something else. You don't have to be a dead languages scholar to guess that this word springs from a Latin source — praecursor, "to run before." A precursor is usually related to what it precedes. It's a catalyst or a harbinger, leading to what follows or providing a clue that it's going to happen. Binging on holiday candy is a precursor to tummy aches and promises to exercise more. Draconian policies in unstable nations are often a precursor to rebellion.

Example Sentences

Another molecule containing nitrogen "is a precursor to how DNA is eventually built," she added.

From Barron's • Apr. 21, 2026

And that is what Moriarty and Hennepin County will test in this case, which, if it succeeds, could be a precursor to charges in other such incidents, including the killings of Pretti and Good.

From Slate • Apr. 17, 2026

But long before that, in 1871, inventor Antonio Meucci received a “caveat,” a precursor to a patent, for his version of a telephone, which he called a speaking telegraph.

From The Wall Street Journal • Apr. 12, 2026

Reports that the recruitment of Lambiase is a precursor to Stella leaving to join Ferrari are said by McLaren insiders to be incorrect.

From BBC • Apr. 9, 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

Related Words

• forerunner
• harbinger