three times vs threefold

three times is not an adjective while threefold is an adjective.

Word	Noun	Adjective	Verb	Adverb
three times	No	No	No	Yes
threefold	No	Yes	No	Yes

As adverbs, three times and threefold are synonyms defined as:

three times (adjective)	threefold (adjective)
	three times as great or many
	having more than one decidedly dissimilar aspects or qualities

three times (adverb)	threefold (adverb)
by a factor of three	by a factor of three