Gymglish french translation for podcast is.... podcast
Me voilà bien avancé ! Que signifie podcast ?
Podcast imposed itself in most languages as it comes from American English and as English has imposed itself throughout the world since WWII. But if you are a French language purist you may call it ballado because a podcast/un ballado can be issued on a MP3 which is a kind of "balladeur". (ballado from balladodiffusion, podcast from podcasting).
podcast has been built from pod-(broad)cast a pod: think of a pea (cosse du pois) or a cockpit of a spaceship (nacelle). The pod here comes from the iPod of Apple. As you know, a podcast is an audiofile (possibly video) digitally recorded so as to be read on a MP3 or other mobile device, or a computer, hence possibly via internet.
You might get more at http://fr.wikipedia.org/wiki/Podcasting