If an object is black then that object absorbs all visible light.
An object that absorbs all the light waves with none reflected back , is perceived as black .
Something is black if it absorbs visible light and doesn't reflect.
What does something look like if it doesn't reflect light?
[a] skull
[b] haze
[c] coal
[d] Smooth
[e] mold
[f] cracks
[g] Black
[h] barrel