hyperactive
Having so much energy that it is hard to stay still.
Hyperactive means having much more energy and activity than usual, to the point where it becomes hard to stay still, focus, or control impulses. A hyperactive child might fidget constantly during class, jump from one activity to another without finishing anything, or struggle to sit through a movie even if they want to watch it.
The word combines “hyper,” meaning excessive or over the top, with “active.” Someone who's hyperactive operates at such a high level that it interferes with what they're trying to do. A hyperactive puppy might bounce around the house, knock things over, and wear everyone out as they try to calm it down.
Some people are naturally hyperactive as part of how their brain works, which can be one feature of a condition doctors call ADHD (Attention Deficit Hyperactivity Disorder). Others might act hyperactive temporarily: excitement before a birthday party or nervousness before a big event can make anyone feel hyperactive for a while.
Being hyperactive is different from simply having lots of energy. An energetic kid can channel their enthusiasm into soccer practice or building an elaborate fort. A hyperactive person has trouble directing that energy anywhere useful. They might start building the fort, then run off to do something else, then remember the fort, then get distracted again, leaving projects half-finished and feeling frustrated.