in Longman fidget means keep moving your hand or feet, esp. when you are bored or nervous. I've read the definition of "hysteria" in the dictionary too. The problem is in Farsi (my language) , hysterically means when you are stressed out or nervous (we say hysteric though:d), so I'd better say when you are nervous and keep moving your leg,,,,, BUT THANK YOU , because I learnt the synonym to