moonbeam(n = noun.phenomenon) moon ray, moon-ray - a ray of moonlight;
is a kind of beam, beam of light, irradiation, light beam, ray, ray of light, shaft, shaft of light
is a part of moon, moonlight, moonshine

   A ray of light from the moon. [1913 Webster]

moonbeam, n. a ray of moonlight.

N  light, ray, beam, stream, gleam, streak, pencil, sunbeam, moonbeam, aurora, day, sunshine, light of day, light of heaven, moonlight, starlight, sunlight, daylight, broad daylight, noontide light, noontide, noonday, noonday sun, glow, glimmering, glint, play of light, flood of light, phosphorescence, lambent flame, flush, halo, glory, nimbus, aureola, spark, scintilla, facula, sparkling, emication, scintillation, flash, blaze, coruscation, fulguration, flame, lightning, levin, ignis fatuus, luster, sheen, shimmer, reflexion, reflection, gloss, tinsel, spangle, brightness, brilliancy, splendor, effulgence, refulgence, fulgor, fulgidity, dazzlement, resplendence, transplendency, luminousness, luminosity, lucidity, renitency, nitency, radiance, radiation, irradiation, illumination, actinic rays, actinism, Roentgen-ray, Xray, photography, heliography, photometer, optics, photology, photometry, dioptrics, catoptrics, chiaroscuro, clairobscur, clear obscure, breadth, light and shade, black and white, tonality, reflection, refraction, dispersion, refractivity, shining, luminous, luminiferous, lucid, lucent, luculent, lucific, luciferous, light, lightsome, bright, vivid, splendent, nitid, lustrous, shiny, beamy, scintillant, radiant, lambent, sheen, sheeny, glossy, burnished, glassy, sunny, orient, meridian, noonday, tide, cloudless, clear, unclouded, unobscured, gairish, garish, resplendent, transplendent, refulgent, effulgent, fulgid, fulgent, relucent, splendid, blazing, in a blaze, ablaze, rutilant, meteoric, phosphorescent, aglow, bright as silver, light as day, bright as day, light as noonday, bright as noonday, bright as the sun at noonday, actinic, photogenic, graphic, heliographic, heliophagous, a day for gods to stoop and men to soar, dark with excessive bright.

N  dimness, darkness, paleness, half light, demi-jour, partial shadow, partial eclipse, shadow of a shade, glimmer, gliming, nebulosity, cloud, eclipse, aurora, dusk, twilight, shades of evening, crepuscule, cockshut time, break of day, daybreak, dawn, moonlight, moonbeam, moonglade, moonshine, starlight, owl's light, candlelight, rushlight, firelight, farthing candle, dim, dull, lackluster, dingy, darkish, shorn of its beams, dark, faint, shadowed forth, glassy, cloudy, misty, blear, muggy, fuliginous, nebulous, nebular, obnubilated, overcast, crepuscular, muddy, lurid, leaden, dun, dirty, looming, pale, confused.