ray vs moonbeam

ray and moonbeam both are nouns.

Word	Noun	Adjective	Verb	Adverb
ray	Yes	No	Yes	No
moonbeam	Yes	No	No	No

As nouns, moonbeam is a hyponym of ray; that is, moonbeam is a word with a more specific, narrower meaning than ray:

Other hyponyms of ray include heat ray, high beam, moon-ray, moon ray, sunbeam, sunray, laser beam, low beam.

ray (noun)	moonbeam (noun)
cartilaginous fishes having horizontally flattened bodies and enlarged winglike pectoral fins with gills on the underside; most swim by moving the pectoral fins	a ray of moonlight
any of the stiff bony spines in the fin of a fish
the syllable naming the second (supertonic) note of any major scale in solmization
a column of light (as from a beacon)
a group of nearly parallel lines of electromagnetic radiation
a branch of an umbel or an umbelliform inflorescence
(mathematics) a straight line extending from a point

ray (verb)	moonbeam (verb)
expose to radiation
extend or spread outward from a center or focus or inward towards a center
emit as rays