Sens

Bourreau de travail, infatigable

Exemple

Meu avô era pé-de-boi: trabalhou na roça a vida inteira.

Mon grand-père était un bourreau de travail : il a travaillé aux champs toute sa vie.

Origine

The image is the ox's foot — slow, heavy, unwavering. The figurative use for a tireless worker is longstanding rural Brazilian Portuguese, and the phrase is also applied to a stubbornly conservative person, a journeyman footballer, or a no-frills, robust car.