Pronunciation: [mˈʌsti] (IPA) 
The word "musty" is spelled with a "u" after the "m" instead of an "o" because it represents the sound /ʌ/ as in "sun" or "luck." In IPA phonetic transcription, the word is written as /ˈmʌsti/. This adjective describes something that has a damp or stale odor, such as an old book or a basement. To avoid the musty smell, it's important to keep things dry and well-ventilated.
The term "musty" is most commonly used as an adjective to describe an unpleasant and stale odor or taste that is reminiscent of dampness, mildew, or mold. It can also be applied to describe a place, object, or even a person that gives off this distinctive odor. When something is described as "musty," it typically implies a lack of freshness and cleanliness, often due to being stored or confined in a damp or poorly ventilated environment.
The musty smell is usually associated with old books, vintage clothes, or basements that have been closed off for a long time. It is caused by the presence of mold or mildew that grows in damp and poorly aerated spaces, where the lack of airflow allows the spores to thrive. Mustiness can also originate from decaying organic matter such as wood or fabric.
Besides the sense of smell, "musty" can also describe something that is old-fashioned, out-of-date, or reminiscent of a bygone era. For instance, a room with antique furniture and classical décor may be described as having a musty atmosphere. In this context, it implies a sense of staleness or an outdated aesthetic.
In summary, "musty" refers to a characteristic odor or taste that is associated with dampness, mold, or mildew. Additionally, it can describe something as outdated or old-fashioned.
Spoiled with damp, mould, or age; having an ill flavour; stale; dull; heavy.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
The word "musty" comes from the Middle English term "musti" or "mousti", which originated in the 14th century. This Middle English word was derived from the Old French word "moiste" or "muste" meaning "damp" or "moldy". The Old French word, in turn, came from Latin "mustus" meaning "fresh or new wine". Over time, the meaning of "musty" evolved to describe a smell or taste associated with dampness, staleness, or an old, moldy environment.
