/pri kerr"seuhr, pree"kerr-/ , n.
1. a person or thing that precedes, as in a job, a method, etc.; predecessor.
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.
3. Chem. , Biochem. 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. Biol. a cell or tissue that gives rise to a variant, specialized, or more mature form.
[ 1375-1425; late ME praecursor forerunner. See PRE-, CURSOR ]
Syn. 1. forerunner. 2. herald.