1. something that comes before and indicates or leads to something else
2. a substance from which another substance is formed
Usage: chemistry; biology

Examples

• The economic downturn was a precursor to widespread unemployment.
• Dark clouds are often a precursor to rain.
• The invention of the telegraph was a precursor to modern communication.
• Scientists studied the precursor chemicals in the reaction.
• Her early paintings were precursors to her later masterpieces.
• The protein acts as a precursor to several important enzymes.
• Political unrest served as a precursor to the revolution.