Here are some terms you might hear used:
* "Ninja clothing" or "Ninja attire": This is the most general term, encompassing all the clothing worn by ninjas.
* "Black clothing": While not all ninjas wore black, black was a popular color for blending into the shadows at night.
* "Jōnin": This term usually refers to a high-ranking ninja, but it can also refer to their distinctive clothing, which is often a dark, formal robe.
* "Shōzoku": This term translates to "clothing" or "costume," and is sometimes used to refer to the clothing worn by ninjas in traditional stories and performances.
Ultimately, the best word to use depends on the context. If you're referring to the clothing worn by ninjas in general, then "ninja clothing" or "ninja attire" is the most appropriate. If you're referring to a specific type of clothing, such as a dark robe, then you can use a more specific term.