entirely vs altogether

entirely is not a noun while altogether is a noun.

Word	Noun	Adjective	Verb	Adverb
entirely	No	No	No	Yes
altogether	Yes	No	No	Yes

As adverbs, entirely and altogether are synonyms defined as:

entirely and altogether: to a complete degree or to the full or entire extent; Completely or entirely

Other synonyms of entirely include all, completely, right, totally, whole, wholly.

entirely (noun)	altogether (noun)
	informal terms for nakedness

entirely (adverb)	altogether (adverb)
to a complete degree or to the full or entire extent; Completely or entirely	with everything included or counted
without any others being included or involved	with everything considered (and neglecting details)
	to a complete degree or to the full or entire extent; Completely or entirely