needs vs necessarily

needs and necessarily both are adverbs.

Word	Noun	Adjective	Verb	Adverb
needs	No	No	No	Yes
necessarily	No	No	No	Yes

As adverbs, needs and necessarily are synonyms defined as:

Other synonyms of needs include inevitably, of necessity.

needs (adverb)	necessarily (adverb)
in such a manner as could not be otherwise	in an essential manner
	as a highly likely consequence
	in such a manner as could not be otherwise