The idiom "a bundle of nerve" refers to someone who is extremely nervous or excitable. There are various synonyms for this phrase, including "jittery," "anxious," "high strung," "tense," "edgy," "fidgety," "nervous wreck," and "on edge." Other similar expressions that one can use to describe this state of being include "jumpy," "hyper," "keyed up," "panicky," "apprehensive," "worried," "uneasy," and "unsettled." When someone is described as a bundle of nerves, it is often a sign that they are experiencing a great deal of stress or anxiety and may need some support or positive distraction to help them calm down.