Antonyms of alight :
unlighted, unlit, gloomy, somber, sunless, cloudy, murky, obscured, shadowlike, shadowy, gray, leaden, pale, lightproof, blackened, dark, darkened, darkish, darkling, dimmed, dusk, dusky, lightless, pitch-black, pitch-dark, tenebrous, choked, damped, dead, doused, extinguished, quenched, smothered, snuffed, stamped, suffocated.
Examples of usage:
The cab passed through into an inner court, stopped, and Gascoigne was ordered to alight. "The Thin Red Line; and Blue Blood", Arthur Griffiths.
My dears, the child came out again in a few minutes, her face all alight. "The Green Satin Gown", Laura E. Richards.
The mouth above the strong, clean- cut chin was singularly sweet, the grey eyes, alight and ardent, meeting the world with a friendly gaiety of expression that seemed to expect and ask for friendliness in return. "The Vision of Desire", Margaret Pedler.