These words refer to a soft radiance, mostly of reflected light. Luminous may describe a source of light, in which case it is very general, indicating the light’s brightness or clarity: luminous stars. Contradictorily enough, it can also specifically suggest a soft or barely perceivable radiance or one enclosed within or seen through something else: dim moonlight on luminous pine needles; the luminous dial of the radio. Lucent and lucid share in these last meanings of luminous , suggesting particularly refracted of suffused light: the lucent pool of water; a lucid , cloudless day. Both, but especially lucid, suggest clarity as a carry-over from what is now their main use, to refer to transparence. Lambent also suggests a radiance of refracted light: the lambent fog surrounding the street lamps. It has a lyrical quality that suggests gentleness or beauty, but can seem over-elegant in some contexts. Refulgent is even more in danger of this possibility, to the point of seeming precious. It specifically indicates a reflected brightness: the refulgent clouds above the setting sun.

Gleaming may indicate a source of light, in which case it merely suggests brightness: gleaming sunlight. In this use, it seems more natural and less formal than luminous. More specifically, gleaming may suggest the brightness of reflected light: the new skyscraper’s gleaming wall of glass. Its overtones in this case are of spotlessness. Gleaming may also suggest obscurity: the daring shapes of fish, faintly gleaming in the depths below the boat. Glistening is almost exclusively restricted to reflected light; except for this, it compares to gleaming , but suggests in addition to dimness an undulating reflection or a most surface: glistening rain-drenched leaves. Lustrous suggests a more mellow reflected light than either gleaming or glistening , applying specifically to the soft shine of any smooth material: the lustrous gold of the wedding ring.