dual vs threefold

dual and threefold both are adjectives.

Word	Noun	Adjective	Verb	Adverb
dual	No	Yes	No	No
threefold	No	Yes	No	Yes

As adjectives, dual and threefold are synonyms defined as:

dual and threefold: having more than one decidedly dissimilar aspects or qualities

Other synonyms of dual include double, three-fold, treble, two-fold, twofold.

dual (adjective)	threefold (adjective)
consisting of or involving two parts or components usually in pairs	three times as great or many
a grammatical number category referring to two items or units as opposed to one item (singular) or more than two items (plural)	having more than one decidedly dissimilar aspects or qualities
having more than one decidedly dissimilar aspects or qualities

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