sombre

dark; right, damn, bloody

“un sombre crétin” — a prize idiot, a complete idiot, an unspeakable imbecile

Inherited from Old French sombre, likely from Latin sub umbra (“in/under the shade”); compare Spanish and Portuguese sombra (“shade, shadow”). Possibly derived through a verb *sombrer, from a Vulgar Latin *subumbrāre (“to shade, enshadow”), though this does not seem necessary. Compare also Old French essombre, with a different prefix.