Initiator

An initiator can refer to:
 * A person that takes an initiative in making something happen.
 * Modulated neutron initiator, a neutron source used in some nuclear weapons
 * Initiator, an Explosive booster
 * Initiator, the first Nuclear chain reaction
 * Pyrotechnic initiator, a device containing a pyrotechnic composition used primarily to ignite other, more difficult to ignite materials
 * Radical initiator, chemical substances that can produce radical species under mild conditions
 * Photoinitiator, chemical substances that produce radical specials upon exposure to light
 * SCSI initiator, the host-side endpoint of a SCSI session
 * Monomeric polyols, such as glycerin, pentaerythritol, ethylene glycol and sucrose, serving as the starting point for polymeric polyols

Biology

 * Initiator element
 * Initiator protein
 * Initiation factor