noun, feminine/ˈpotɾa/plural: potras
hernia (especially an umbilical or scrotal hernia); luck, dumb luck, a fluke
“por potra”
Synonyms: chorra, chiripa, suerte, coña
Unknown. The Real Academia Española (DRAE) considers it of uncertain origin. The colloquial sense of "luck" derives from its primary medical sense, as people suffering from a hernia could allegedly predict rain or weather changes due to their aches, which was perceived as a lucky "sixth sense."