Literal translation
he's the drum of Cassis
Meaning
he's a chatterbox, hard to stop once started
Explanation
Said of someone talkative, hard to interrupt, in the full formula un sòu pèr coumença e vint pèr l'aplanta (a penny to start and twenty to stop it). Cassis, a small port east of Marseille, may have lent its name to a real drummer who loved playing too much, but the origin might also lie in a nickname for thunder, lou tambour dei grapaud, since storms arrive from that direction along the coast. Mistral already recorded the formula in the nineteenth century with a more modest stopping price, five sous, a sign that the cost of silencing the chatterbox has kept climbing.