gloomily dark; shadowy; dimly lighted: a somber passageway.
dark and dull, as color, or as things in respect to color: a somber dress.
gloomy, depressing, or dismal: a somber mood.
extremely serious; grave: a somber expression on his face.
Also, especially British,sombre.
Origin: 1750–60; < Frenchsombre,Middle French, probably noun derivative of *sombrer to make shady < Vulgar Latin*subumbrāre, equivalent to Latinsub-sub- + umbrāre to cast a shadow, derivative of umbra shade
1760 (earlier sombrous, c.1730), from Fr. sombre "dark, gloomy," from O.Fr. sombre, from L.L. subumbrare "to shadow," from sub "under" + umbra "shade, shadow," from PIE *andho- "blind, dark" (see umbrage).