Q: It seems as if “champ at the bit” has suddenly morphed into “chomp at the bit.” Why this shift? Has the new form become standard?
A: The traditional expression is “champ at the bit,” which means to show impatience. But a growing number of people are choosing “chomp at the bit.” I just did a Google search for both phrases. The results: 942 hits for “champ” and 14,900 for “chomp.” Like it or not, the “chomps” are making a chump of me. (I will resist making puns about Noam Chomsky!)
I still recommend using “champ at the bit,” especially when one’s language should be at its best, but I suspect that “chomp at the bit” will eventually become standard American English. The American Heritage Dictionary of the English Language lists only “champ at the bit.” But Merriam-Webster’s Collegiate Dictionary now includes both expressions without qualification.
The word “champ” has meant bite, as in a horse’s biting impatiently at a bit, since at least 1577, according to the Oxford English Dictionary. The word “chomp” has been a variant of “champ” since at least 1645, though the early references deal with chomping on food rather than at metal bits.
I can’t tell you why people began substituting “chomp” for “champ” in the first place. A few years ago, the linguists Geoffrey Pullum and Mark Liberman came up with the term “eggcorn” to describe such a substitution. (The term comes from the substitution of “egg corn” for “acorn.”)