To move one's fingers or hands in a nervous or aimless fashion
A state of nervous restlessness or agitation.
It also includes how sedentary or active your job is, and whether you fidget a lot or sit still.
They don't learn their lessons, they don't listen, they fidget and play, and prevent others from learning.
fidget a lot.
They often fidget and sit in distorted postures to try to gain stability.
fidget around like a broker without his first cup of coffee.