catalyst

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.

Something that encourages progress or change.

Economic development and integration are working as a catalyst for peace.

It was a morning baptized by my first cup of coffee, freshly brewed over a gravel-bar fire, while they celebrated with the stronger catalyst of sour-mash whiskey in their fishing-vest cups.

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.

A catalytic converter.

An object that facilitates the casting of a spell (such as a magic wand).