1. having a stale, damp, or moldy smell or taste
2. old-fashioned or outdated
Usage: informal

Examples

• The basement had a musty smell from years of dampness.
• She opened the windows to air out the musty attic.
• The old books in the library smelled musty.
• His musty ideas about technology needed updating.
• The musty odor disappeared after we cleaned the room.
• The antique shop had a distinctly musty atmosphere.