initiator
Concise Oxford English Dictionary © 2008 Oxford University Press:
initiator/ɪˈnɪʃieɪtə(r)/
▶noun
- 1 a person or thing that initiates.
- 2 Chemistry a substance which starts a chain reaction.
- 3 an explosive or device used to detonate the main charge.
'initiator' also found in these Oxford entries:

