absolute darkness / (Buddhism) a complete lack of virtue or wisdom / (color) pure black

grey bunting

bighead carp (Hypophthalmichthys nobilis)

Pacific reef heron (Egretta sacra)

black key (of a piano, etc.)

Berkshire pig

rye

rotary dial telephone / (slang) Kim Jong-un

(Internet slang, especially anime and manga fandom) events or things from the past which one wants to whitewash/erase from history (due to it being embarrassing, poorly received, etc.); dark past

a common crane