dismal vs drab

dismal is not a noun while drab is a noun.

Word	Noun	Adjective	Verb	Adverb
dismal	No	Yes	No	No
drab	Yes	Yes	No	No

As adjectives, dismal and drab are synonyms defined as:

Other synonyms of dismal include blue, dark, dingy, disconsolate, drear, dreary, gloomy, grim, sorry.

dismal (noun)	drab (noun)
	a dull greyish to yellowish or light olive brown

dismal (adjective)	drab (adjective)
causing dejection	of a light brownish green color
	lacking brightness or color; dull
	causing dejection
	lacking in liveliness or charm or surprise