Aphotic and Pitch-dark

Aphotic adjective - Lacking light; especially not reached by sunlight.

Pitch-dark and aphotic are semantically related in lack of light topic. In some cases you can use "Pitch-dark" instead an adjective "Aphotic".

Pitch-dark adjective - Being without light or without much light.

Aphotic and pitch-dark are semantically related in lack of light topic. Sometimes you can use "Aphotic" instead an adjective phrase "Pitch-dark".