Trigger That Starts a Reaction
This page is the CodyCross answer for the clue below from Campsite Adventures, Group 836, Puzzle 1 (Bird Watching).
Question is: Trigger That Starts a Reaction
and the answer is: CATALYST
Word Meaning:
CATALYST — (chemistry) A substance that increases the rate of a chemical reaction without being consumed in the process.
Definitions from Wiktionary.