accelerant

noun

1. Any substance that can bond, mix, or disturb another substance and cause an increase in the speed of a natural or artificial chemical process.
2. A substance that accelerates the development of a fire; especially some petroleum product used to spread an act of arson
3. A substance used to catalyze the vulcanization of rubber
4. (metaphoric) Something that speeds up a process or speeds up the uptake of something.