The Collaborative International Dictionary of English v.0.48:

Fusty \Fusty\, a. [Compar. Fustier; superl. Fustiest.] [See
   2d Fust.]
   1. Moldy; musty; ill-smelling; rank. "A fusty nut." "Fusty
      plebeians." --Shak.
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   2. Moping. [Archaic]
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            A melancholy, fusty humor.            --Pepys.
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