"Champ at the bit" is an idiomatic expression used to describe an individual who is eagerly waiting for something to happen. However, there are several synonyms that can be used to convey this meaning including "itching", "restless", "antsy", "agitated", "impatient", and "fidgety". Each of these words describes the feeling of someone who is excited and impatiently waiting for something to happen. While "champ at the bit" is a commonly used phrase, incorporating these synonyms in your writing or conversation can provide a more varied and nuanced vocabulary. These synonyms can be especially useful when trying to convey a sense of anticipatory excitement or anxiety.