- The definition of hyperactive is having extreme levels of activity.
An example of someone hyperactive is a person who can bounce around all day and never tire out.
extremely, esp. abnormally, active
- Highly or excessively active: a hyperactive thyroid gland.
- a. Characterized by or displaying overactivity: hyperactive behavior; hyperactive children.b. Having attention deficit hyperactivity disorder. Not in scientific use.
(comparative more hyperactive, superlative most hyperactive)