catalyst

noun5

1. •
   A substance that increases the rate of a chemical reaction without being consumed in the process.

   • Enzymes, the catalysts of biological systems, are remarkable molecular devices that determine the pattern of chemical transformations. — 1988
2. •
   Something that encourages progress or change.

   • Economic development and integration are working as a catalyst for peace.
3. •
   An inciting incident that sets the successive conflict into motion.

   • The current view by both Labour and Conservative politicians is that the state of the UK railway is unsustainable, and the pandemic acted as a catalyst in exposing its weaknesses. — 2023
4. •
   A catalytic converter.
5. •
   An object that facilitates the casting of a spell (such as a magic wand).