Primarily used in medical, psychological, or educational contexts to describe excessive motor activity, especially in children. Often associated with ADHD (注意欠如・多動症).
See also: ＡＤＨＤ
This child has a tendency toward hyperactivity and cannot sit still during class.
Hyperactivity is one of the main symptoms of ADHD.
Compound of 多 (many, excessive) and 動 (movement). A modern medical term likely coined as a translation of 'hyperactivity'.