ENGLISH
REFERENCE

musty

adj.
B2 Upper Intermediate US //ˈməsti// UK //mˈʌsti// musty Archaic

adj. having a strong, unpleasant smell like old books or damp clothes. You use this to describe things that have been stored in a dark, humid place for a long time.

adj. having a strong, unpleasant odour resembling that of old paper or damp wool. Often used to describe objects that have been stored in a poorly ventilated environment.


SIMPLE

The old library smelled musty and damp.

CONTEXTUAL

I had to open the window because the old trunk smelled musty after being in the attic for years.

COMPLEX

The musty scent of the abandoned warehouse was a stark contrast to the sterile, modern offices of the new headquarters.

Synonyms
Etymology 1

The adjective is derived from Late Middle English musty; further origin uncertain, possibly from one of the following: From Anglo-Norman muste, moste, variants of moiste, muiste (“moist”), from Old French moiste (“clammy, damp, moist, wet”) (modern French moite (“muggy; sticky, sweaty”)), from a blend of Vulgar Latin mucidus (from Latin mūcidus (“mouldy, musty”), from Old Latin mūceō (“to be mouldy or musty”) + -idus (suffix meaning ‘tending to’, forming adjectives)) + Latin mustum (“unfermented or partially fermented grape juice, must; new wine”) (from mustus (“fresh; young; unfermented”), from Proto-Indo-European mus-, mews- (“damp; moss”)). * From another language derived from the above Latin words (compare the cognates below). * A variant of Middle English mosty, moisti (“damp, humid, wet, moisty; of fruit: moist and juicy”) [and other forms] (perhaps influenced by must (“fruit (usually grape) juice which has been or will be fermented”)), from moist, moiste (“damp, humid; moist, wet; well-irrigated, well-watered; liquid; of ale: new; (figuratively) not withered, fresh; carnal, lascivious; raw, undisciplined”) (from Old French moiste: see above) + -i (suffix forming adjectives). Compare Middle French moisi (“mouldy”), an adjective use of the past participle of moisir (“(to cause) to go mouldy, to moulder”) (modern French moisir), from Latin mūcēre, the present active infinitive of Old Latin mūceō (“to be mouldy or musty”): see above. The English word is analysable as must (“mould; mustiness”) + -y (suffix meaning ‘having the quality of’ forming adjectives); however, must is thought to be a back-formation from musty. The noun and verb are derived from the adjective. Cognates * Catalan mústic, musti (“wilted, withered; gloomy, sad”) * Galician murcho, mucho (“wilted, withered”) * Old Occitan moste (Occitan moste, mosti, musti (“damp, wet”) (Gascon)) * Portuguese murcho (“wilted, withered; gloomy, sad”) * Spanish mustio (“wilted, withered; gloomy, sad”)

Etymology 2

From musth (“time during which male elephants exhibit increased levels of sexual activity and aggressiveness”) + -y (suffix meaning ‘having the quality of’ forming adjectives).

© 2026 English Reference