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

Not much different than it was in 1792, when 24 brokers established the precursor to the New York Stock Exchange, selling shares of shipping and insurance concerns to the city’s leading citizens.

From Barron's • Apr. 15, 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

Musk, OpenAI’s then principal financial supporter, had asked Brockman and Chief Scientist Ilya Sutskever to make a spreadsheet listing every employee and what important contribution they had made—a classically Muskian precursor to staff cuts.

From The Wall Street Journal • Mar. 28, 2026

These proteins, writes Mr. Gifford, can also help reverse nonalcoholic fatty-liver disease, which is often a precursor to diabetes.

From The Wall Street Journal • Mar. 16, 2026

It merged in 1994 with another company in a 2.4-billion-dollar deal, a precursor to the dot-com boom.

From "A Deadly Wandering: A Mystery, a Landmark Investigation, and the Astonishing Science of Attention in the Digital Age" by Matt Richtel

Related Words

• forerunner
• harbinger