MUSTY

fusty, musty, frowsty

(adjective) stale and unclean smelling

moldy, mouldy, musty

(adjective) covered with or smelling of mold; “moldy bread”; “a moldy (or musty) odor”

Source: WordNet® 3.1

Etymology

Adjective

musty (comparative mustier, superlative mustiest)

Having a stale odor.

Source: Wiktionary

Mus"ty, a. [Compar. Mustier; superl. Mustiest.] Etym: [From L. mustum must; or perh. fr. E. moist. Cf. Must, n., Moist.]

1. Having the rank, pungent, offencive odor and taste which substances of organic origin acquire during warm, moist weather; foul or sour and fetid; moldy; as, musty corn; musty books. Harvey.

2. Spoiled by age; rank; stale. The proverb is somewhat musty. Shak.

3. Dull; heavy; spiritless. "That he may not grow musty and unfit for conversation." Addison.

Source: Webster’s Unabridged Dictionary 1913 Edition