twofold vs double

twofold is not a noun while double is a noun.

Word	Noun	Adjective	Verb	Adverb
twofold	No	Yes	No	Yes
double	Yes	Yes	Yes	Yes

As adjectives, twofold and double are synonyms defined as:

Other synonyms of twofold include doubled, two-fold.

As adjectives, twofold and double are synonyms defined as:

twofold and double: having more than one decidedly dissimilar aspects or qualities

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

twofold (noun)	double (noun)
	a base hit on which the batter stops safely at second base
	raising the stakes in a card game by a factor of 2
	a quantity that is twice as great as another
	someone who closely resembles a famous person (especially an actor)
	a stand-in for movie stars to perform dangerous stunts

twofold (adjective)	double (adjective)
twice as great or many	used of homologous chromosomes associated in pairs in synapsis
having more than one decidedly dissimilar aspects or qualities	used of flowers having more than the usual number of petals in crowded or overlapping arrangements
	having two meanings with intent to deceive
	large enough for two
	twice as great or many
	consisting of or involving two parts or components usually in pairs
	having more than one decidedly dissimilar aspects or qualities

twofold (verb)	double (verb)
	increase twofold
	hit a two-base hit
	do double duty; serve two purposes or have two functions
	make or do or perform again
	bend over or curl up, usually with laughter or pain
	make a demand for (a card or suit)