E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Pit-a-pat.
My heart goes pit-a-pat. Throbs, palpitates. “Pat” is a gentle blow (Welsh, ffat), and “pit” is a mere ricochet expletive. We have a vast number of such ricochet words, as “fiddle - faddle,” “harum - scarum,” “ding-dong,” etc.
