IPA: /ɪɡˈnaɪtəbl/
KK: /ɪgˈnaɪtəbl/
Able to catch fire or be set on fire.
The ignitible materials should be stored carefully away from heat sources.
Ignitible is formed from "ignis" (meaning fire) and the suffix "-ible" (meaning capable of). The word describes something that is capable of being ignited or set on fire.
Think of 'ignis' meaning fire, and remember that 'ignitible' refers to something that can catch fire.