What is a Japanese teapot called?

A kyūsu (急須) is a traditional Japanese teapot mainly used for brewing green tea.
The common misconception is that a kyūsu always has a side handle. However, the word "kyūsu" merely means "teapot", even though in common usage kyūsu usually does refer to a teapot with a side handle.
The two most common types of kyūsu are yokode kyūsu (横手急須, side hand(le) teapot), which has a side handle and which is the more common type, and ushirode kyūsu (後手急須, back hand(le) teapot), which has a rear handle, just like teapots in other parts of the world;[1] there are also uwade kyūsu (上手急須, top hand(le) teapot).