Sasanian dress is the type of clothing people wore during the Sasanian Empire, which was a long time ago in a place called Persia (now Iran). It was a very fancy and colorful kind of clothing, with lots of decorations and patterns on it.
Imagine a big rectangle that's longer than you are tall. This rectangle is called a tunic, and it's what men and women wore over their undershirts. The tunics could be made out of wool, silk, or other materials, and they had a lot of different designs on them. Some had pictures of animals or plants, some had patterns of dots or lines, and others had all different colors.
Women's tunics were usually more elaborate than men's, with longer sleeves that might be decorated with fringes or tassels. They would also wear a special type of belt that was tied in a knot at the front.
Men and women both wore pants under their tunics, but men's pants were more loose-fitting and women's were more like leggings. They would also wear shoes or boots that could be made out of leather or felt.
To keep themselves warm in cold weather, both men and women would wear a cloak over their tunics. These cloaks could be short or long, and were made out of lots of different materials like wool or fur.
Overall, Sasanian dress was very fancy and colorful, with lots of different designs and patterns on it.