come down vs wan

come down is not an adjective while wan is an adjective.

Word	Noun	Adjective	Verb	Adverb
come down	No	No	Yes	No
wan	No	Yes	Yes	No

As verbs, wan is a hyponym of come down; that is, wan is a word with a more specific, narrower meaning than come down:

Other hyponyms of come down include contract, get, take, canker.

come down (adjective)	wan (adjective)
	abnormally deficient in color as suggesting physical or emotional distress
	(of light) lacking in intensity or brightness; dim or feeble
	lacking vitality as from weariness or illness or unhappiness

come down (verb)	wan (verb)
get sick	become pale and sickly
be the essential element
criticize or reprimand harshly
move downward and lower, but not necessarily all the way
fall from clouds