Champ at the bit

To show impatience or frustration when delayed. Examples "I am so excited for the next Star Wars movie. I am champing at the bit to go see it" Etymology From champ (verb) (“to chew noisily”) + bit (“part of horse's harness held in its mouth”); horses tend to chew on their bits when impatient at waiting. Alternate Forms Champing at the bit Chomping at the bit Sources Wiktionary