The term 'full of nervous energy' can be described by three five-letter words: ANTSY, JUMPY, and wired. ANTSY is an informal word meaning restless or impatient, often due to anxiety or excitement. JUMPY is an adjective used to describe someone who is easily startled or agitated. Wired is an informal word meaning full of energy, often due to being overly excited or anxious. All three words are used to describe someone who is full of nervous energy.