1. more active than is normal or desirable

Examples

• The child has an overactive imagination and creates elaborate fantasy worlds.
• Her overactive thyroid caused weight loss and restlessness.
• The overactive security system triggered false alarms all night.
• His overactive mind kept him awake worrying about tomorrow’s presentation.
• The overactive immune system attacked healthy tissue.
• She has an overactive bladder that requires frequent bathroom breaks.