noun
or ig·ni·tor -īd.ə(r)
( -s )
: one that ignites: as
a. : a charge usually of black gunpowder used to facilitate the ignition of a propelling charge and sometimes of a bursting charge
b. : a device for igniting fuel mixture (as in an internal-combustion engine, a jet engine, or a rocket engine)
c. : a separately energized electrode used for restriking the arc in an ignitron