A mini katana is commonly referred to as a tanto. Tanto is a Japanese term that translates to "short sword" or "knife." It typically denotes a blade length of less than one shaku (approximately 30 centimeters or 12 inches).

Traditionally, tanto blades were designed for stabbing and slashing in close-quarters combat. They were primarily used by samurai as backup weapons or for situations that required a shorter blade. Tanto blades were also used for ceremonial purposes or as status symbols. Their compact size made them convenient for everyday carry and practical for various tasks.

In modern times, the term "tanto" is often used to describe a small version of a katana or a katana-inspired knife. These mini katanas, sometimes marketed as "tactical tantos" or "miniature katanas," are typically folding knives or fixed-blade knives designed with a tanto-style blade shape. They retain the characteristic straight cutting edge, but with a sharp angular tip.

The term "tanto" is used broadly to describe both historical short swords and contemporary knife designs. So, if you are referring to a small-sized katana or a knife with a tanto-style blade, it can be commonly referred to as a mini katana or a tanto.