chomp 
(chŏmp)
(chŏmp)v. chomped, chomp·ing, chomps
v.tr.
To chew or bite on noisily: a horse chomping oats.
v.intr.
To chew or bite on something repeatedly: chomping on a cigar.
n.
Idiom: The act or an instance of vigorous biting: "He finished the last of his sandwich with a single chomp" (Anne Tyler).
chomp at the bit
To show impatience at being held back or delayed.
[Variant of CHAMP1.]
Usage Note: Historically, to bite down with the teeth was to champ, not to chomp, and someone who was impatient at being held back was said to champ at the bit rather than to chomp at the bit. The version of this idiom using the variant chomp first became popular in the mid-1900s and is now the more common form, but both were rated as broadly acceptable in our 2015 Usage Panel ballot, with 70 percent of the Panel accepting the form with champ and 77 percent accepting the form with chomp.