catalyst
1. [ noun ] (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected
Synonyms: accelerator
Related terms: anticatalyst activator enzyme platinum_black biocatalyst chemistry
2. [ noun ] something that causes an important event to happen
Examples:

"the invasion acted as a catalyst to unite the country"

Related terms: causal_agent
Similar spelling:   catalysis
  catalyse
  catalyze
  catalexis
  cattleship
  catalectic
  catwalk
  catalog
  catalase