“champing at the bit”

• chomping at the bit → champing at the bit See the fix →

'Champ' is the older verb — a horse repeatedly biting the metal bit between its teeth. Modern English shifted toward 'chomp,' but the set phrase preserves 'champing.' Both are now widely accepted, but 'champing' is the original.

Champing is the horsey word. Chomping works too — editors tolerate it — but 'champing' is the purist's call.