Definition from Wiktionary, the free dictionary
- præcursor (chiefly obsolete)
precursor (plural precursors)
- That which precurses, a forerunner, a predecessor, an indicator of approaching events.
2013 September-October, Katie L. Burke, “In the News”, American Scientist:
- Oxygen levels on Earth skyrocketed 2.4 billion years ago, when cyanobacteria evolved photosynthesis: […] . The evolutionary precursor of photosynthesis is still under debate, and a new study sheds light. The critical component of the photosynthetic system is the “water-oxidizing complex”, made up of manganese atoms and a calcium atom.
- (chemistry) One of the compounds that participates in the chemical reaction that produces another compound.