IPA: /kəmˈbʌstɪv/
KK: /kəmˈbʌstɪv/
Relating to or involved in the process of burning or combustion.
The combustive materials in the engine help it to run efficiently.
Combustive → It is formed from "com-" (meaning together) and "bustion" (from Latin "combustio", meaning burning). The word "combustive" refers to something that is capable of causing or relating to burning.
Think of 'burning' ('bustion') happening 'together' ('com-') — that's why combustive means related to burning.