Literal translation
to shit in one's trousers
Meaning
to be scared, a coward
Explanation
To be afraid, to be a coward. The image of soiling oneself from fright is shared across many languages, and using the Provençal form clearly softens its crudeness. The word braio (trousers), always plural as it once was in French, gave the noun cago-ei-braio for a coward. Whoever gets called this can answer with the rhymed retort that the mess is his own and the trousers are paid for. The literal sense still applies to a young child, but for an adult it becomes necessarily figurative.