Aphotic and Pitch black

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

Pitch black and aphotic are semantically related In some cases you can replace phrase "Pitch black" with "Aphotic", this terms are similar.

Pitch black noun - A very dark black.

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