Entry 2 senses Webster, 1913 Fusty /fŭs'-tēˌ/ · IPA /ˈfʌsti/ 01 a. Moldy; musty; ill-smelling; rank. 1. Moldy; musty; ill-smelling; rank. 2. Moping.[Archaic] “A melancholy, fusty humor.” — Pepys.