Tensa Zangetsu is a significant form of Ichigo Kurosaki's Zanpakuto, Zangetsu, in the manga and anime series "Bleach." It is the name given to Ichigo's Bankai, which is the second and most advanced form of a Zanpakuto.

When Ichigo activates his Bankai, Zangetsu undergoes a transformation and takes on the appearance of a sleek, black sword with a long, chain-like blade extending from the hilt. The name "Tensa Zangetsu" translates to "Heavenly Chain Moon Cutter" or "Heavenly Chain Slaying Moon."

Tensa Zangetsu grants Ichigo enhanced speed, strength, and agility, enabling him to move and strike with incredible speed and precision. It also allows him to fly and move through the air effortlessly using the chain-like blade. With Tensa Zangetsu, Ichigo's combat capabilities are significantly augmented, making him a formidable force in battle.

It's important to note that Tensa Zangetsu represents a specific stage of Ichigo's power and development throughout the series. As the story progresses, Ichigo gains further transformations and power-ups, each with its unique name and abilities, such as the true form of Zangetsu called "Zangetsu - Mugetsu."