A triple-edged sword is often referred to as a “trident”. In mythology and certain weaponry contexts, the trident is a three-pronged spear-like weapon, which has three points (or “edges”) instead of the usual single edge found in traditional swords. It’s commonly associated with gods such as Poseidon in Greek mythology or Neptune in Roman mythology.
However, if you’re referring to a sword specifically with three distinct edges, it could be a conceptual or fictional design, as most traditional swords have one or two edges. If it’s something from a specific fictional universe or concept, it might have a unique name depending on the context.