- The definition of mousy is a shy and nervous person, or someone with a drab appearance.
An example of mousy is a person who is anxious around others and doesn't want to speak in group settings.
- Resembling a mouse, especially:a. Having a drab, pale brown color: mousy hair.b. Having small sharp features: a mousy face.c. Quiet; timid; shy.
- Infested with mice.
(comparative mousier, superlative mousiest)