mustiness mustily • mustnt · · · Info · Definitions · Synonyms · Characters · · mustiness · · Text Latin · · Script 9 · · Length Definitions · · · (noun) the quality of smelling or tasting old or stale or mouldy. Synonyms: must, moldiness. · · Noun Definition 1 Synonyms · · · must · · Synonym 1 moldiness · · Synonym 2 Characters · · e latin small letter e U+0065 i latin small letter i U+0069 m latin small letter m U+006D n latin small letter n U+006E s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075