initiator

Plural: initiators

Noun

• a person who initiates a course of action
• One who initiates.
• A substance that initiates a chain reaction or polymerization.
• A component of a nuclear weapon that produces a burst of neutrons to start the chain reaction.
• A task (in a mainframe computer) that initiates multiple jobs.
• A material whose presence in the body eventually leads to cancer.

Synonyms

instigator