overactive

2 definitions • 4 examples

(of part of the body) producing too much of a substance, or reacting too quickly:

With an overactive thyroid, metabolism speeds up.

Over-active bladder is a frequent and urgent need to use the toilet.

(of someone's mind or imagination) thinking too much about things:

She had dismissed the voices as figments of her overactive imagination.

I have a terribly over-active mind and anything that's happened in the day whirls around my head endlessly.