dull; cheerless; lacking in spirit, brightness, etc.

having the color drab.

dull gray; dull brownish or yellowish gray.

any of several fabrics of this color, esp. of thick wool or cotton.

noun

asepticism , blandness , colorlessness , dreariness , dryness , flatness , flavorlessness , insipidity , insipidness , jejuneness , lifelessness , sterileness , sterility , stodginess , vapidity , vapidness , weariness