incombustible
UK /ˌɪŋkəmˈbʌstɪbəl/ US /ˌɪŋkəmˈbʌstɪbəl/
adj 1noun 1
Definitions
adj
1
Not capable of catching fire and burning; not flammable.
The ash represents the more incombustible mineral matter, usually of the nature of clay or slate.
noun
1
Any substance that is not flammable.
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