Jet and Pitch-dark

Jet adjective - Of the blackest black; similar to the color of jet or coal.

Pitch-dark and jet are semantically related in black topic. In some cases you can use "Pitch-dark" instead an adjective "Jet".

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

Jet and pitch-dark are semantically related in black topic. You can use "Jet" instead an adjective phrase "Pitch-dark", if it concerns topics such as dark, very dark in color.