chiaroscuro etc.(light)Light. noctivagation. [perfectly black objects] black body
hohlraum [Phys.]
black hole
dark star
dark matter, cold dark matter.
Verbs
be dark etc.adj.. darken, obscure, shade
dim
tone down, lower
overcast, overshadow
eclipse
obfuscate, offuscate
obumbrate, adumbrate
cast into the shade becloud, bedim, bedarken
cast a shade, throw a shade, spread a shade, cast a shadow, cast a gloom, throw a shadow, spread a shadow, cast gloom, throw gloom, spread gloom. extinguish
put out, blow out, snuff out
doubt. turn out the lights, douse the lights, dim the lights, turn off the lights, switch off the lights.
Adjectives
dark, darksome, darkling
obscure, tenebrious, sombrous, pitch dark, pitchy, pitch black