moonstruck vs lunatic

moonstruck is not a noun while lunatic is a noun.

Word	Noun	Adjective	Verb	Adverb
moonstruck	No	Yes	No	No
lunatic	Yes	Yes	No	No

As adjectives, moonstruck and lunatic are synonyms defined as:

moonstruck and lunatic: insane and believed to be affected by the phases of the moon

moonstruck (noun)	lunatic (noun)
	an insane person
	a reckless impetuous irresponsible person

moonstruck (adjective)	lunatic (adjective)
insane and believed to be affected by the phases of the moon	insane and believed to be affected by the phases of the moon