Opposite words for lambent:
darksome, unlit, palish, darkling, gray, lightless, unbright, tenebrous, shady, pale, darkish, blackened, pitch-black, cloudy, dusky, obscure, unbrilliant, murky, lackluster, dull, shadowy, dim, dark, obscured, shadowlike, gloomy, pitch-dark, leaden, sunless, dimmed, darkened, somber.
Usage samples:
  1. Ishmael doubted this; somehow, waiting there in that still room, whose tranquillity seemed so much of its essence as to be more than a mere absence of noise, waiting and gazing at the strip of sunlit High Street that seemed lambent by contrast with the dimness within, Ishmael conceived a dislike to Killigrew.
    "Secret Bread", F. Tennyson Jesse.
  2. Daggers of lambent fever race through my brain incessant.
    "Prince Zaleski", M.P. Shiel.
  3. It must be restrained, controlled, guarded, that fierce conflagration; but our joy cannot only consist of pure, clear, lambent, quiescent elements.
    "Joyous Gard", Arthur Christopher Benson.
  4. She stood with one hand touching her veil's hem, the other resting on the low, carved arm of the throne, and at the coming and going of her breath her jewels made the light lambent with the indeterminate colours of those strange, joyous banners floating far above her head.
    "Romance Island", Zona Gale.