Carbon dioxide is incombustible, since it is, like water, a product of combustion.
It is a transparent gas, which is incombustible and extinguishes flame.
I think I may say I am old and incombustible enough to be trusted.
The fuse wire is usually enclosed in an incombustible holder.
It was burned in incombustible flax, with the orange-tree on which it used to perch.