Champing

They are champing to start at once.

Source: tatoeba (52167)

I'm champing at the bit like a wild horse.

Source: tatoeba (3479857)

A small boy stood champing gum.

Source: tatoeba (7867936)

So they took their seats, and supper was set before them: kids stuffed with walnuts and almonds and pistachios; herons in sauce cameline; chines of beef; geese and bustards; and great beakers and jars of ruby-hearted wine. Right fain of the good banquet were Corinius and his folk, and silence was in the hall for awhile save for the clatter of dishes and the champing of the mouths of the feasters.

Source: tatoeba (8863911)