sombre

Etymology

Borrowed from French sombre (“dark”), from Old French sombre, from a verb *sombrer or Latin sub- + umbra. Compare Spanish sombra (“shade; dark part of a picture; ghost”).

adj

1. Dark; gloomy; shadowy, dimly lit.
   The lady led him into a sombre hallway and disappeared. A moment later the windowless chamber was illuminated by the entry of a heavenly creature emitting a radiance prone to pierce the heart of any youth exposed to it. 2015, Hermann Kauders, Before The Cock Crows, page 9
2. Dull or dark in colour or brightness.
   His tall and slender figure, dressed in sombre black, his hair of that peculiar reddish auburn so rarely seen, his flashing black eyes, in which a fitful fire seemed for ever burning; all combined to give something almost of a demoniac air ... 1877, The Black Band; or, The Mysteries of Midnight, page 47
3. Melancholic, gloomy, dreary, dismal; grim.
   A sombre mood, very sombre in fact, thought Hennessey, as he stood against the wall observing the procedure for the police. He had not known a mood more sombre to have previously descended on the room. 2012, Peter Turnbull, Aftermath, Severn House Publishers Ltd
4. Grave; extremely serious.
   a sombre situation

noun

1. (obsolete) Gloom; obscurity; duskiness.

verb

1. To make sombre or dark; to make shady.