Portafortuna literally translates to "lucky charm" or "talisman". It's a charming and somewhat whimsical word that isn't found in every song, making it stand out.
In the context of the song, the protagonist, an electrician, survives being run over by a truck because he has a portafortuna given to him by his aunt. This word adds a touch of quirky humor and a sense of the absurd to the narrative, perfectly fitting the song's surreal tone.
Welcome to the bizarre and hilarious world of "38 Luglio"! The song tells what it calls a "terrible film" about an electrical technician. This isn't just any technician; he's the one who invented the battery, only to have electric light discovered four days later, making his invention almost useless. This sets the stage for a series of completely absurd and disconnected events.
From a love affair described as a "bombardment" to a scene where the technician lies on the ground to be run over by a truck, the story gets stranger and stranger. He survives thanks to a lucky charm from his Aunt Woller: a battery-powered crowbar. The tale also includes an impossible date (July 38th), a shy Indian chief who never shows up, and a referee awarding victory to our hero because of an octopus's eyebrow injury. The song is a masterpiece of surreal, deadpan humor, creating a story where absolutely nothing makes sense, and that's the whole point.