Something that comes before something else and indicates its approach.

An indication or warning of something that is about to happen.

पूर्ववर्ती

English Usage: "The invention of the telephone was a precursor to modern communication technology."

Hindi Usage: "टेलीफोन का आविष्कार आधुनिक संचार तकनीक का पूर्ववर्ती था।"

A substance that participates in a chemical reaction to form another substance.

पदार्थ

English Usage: "In the synthesis of drugs, precursor chemicals are essential."

Hindi Usage: "औषधियों के संश्लेषण में, पूर्ववर्ती रासायनिक पदार्थ आवश्यक हैं।"