virtually vs nigh

virtually is not an adjective while nigh is an adjective.

Word	Noun	Adjective	Verb	Adverb
virtually	No	No	No	Yes
nigh	No	Yes	No	Yes

As adverbs, virtually and nigh are synonyms defined as:

virtually and nigh: (of actions or states) slightly short of or not quite accomplished; all but

Other synonyms of virtually include about, almost, most, near, nearly, well-nigh.

virtually (adjective)	nigh (adjective)
	not far distant in time or space or degree or circumstances
	being on the left side

virtually (adverb)	nigh (adverb)
in essence or effect but not in fact	near in time or place or relationship
(of actions or states) slightly short of or not quite accomplished; all but	(of actions or states) slightly short of or not quite accomplished; all but