Synonyms: catalyst
Definition: something that causes an important event to happen
Usage: the invasion acted as a catalyst to unite the country
Similar words: causal agency, causal agent, cause
Definition: any entity that produces an effect or is responsible for events or results
Synonyms: accelerator, catalyst
Definition: (chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected
Similar words: activator
Definition: (biology) any agency bringing about activation; a molecule that increases the activity of an enzyme or a protein that increases the production of a gene product in DNA transcription