must vs necessary

must and necessary both are nouns.

Word	Noun	Adjective	Verb	Adverb
must	Yes	Yes	No	No
necessary	Yes	Yes	No	No

As nouns, necessary is a hypernym of must; that is, necessary is a word with a broader meaning than must:

Other hypernyms of must include essential, necessity, requirement, requisite.

must (noun)	necessary (noun)
the quality of smelling or tasting old or stale or mouldy	anything indispensable
grape juice before or during fermentation
a necessary or essential thing

must (adjective)	necessary (adjective)
highly recommended	absolutely essential
	unavoidably determined by prior circumstances