skysail
noun [ C ] sailing specialized uk/ˈskaɪ.seɪl/ us/ˈskaɪ.seɪl/
天帆
a sail that is usually the top sail on a mast (= a tall pole) on a sailing boat
A skysail is the uppermost sail in many old square-rigged ships, though sometimes topped by a moonraker. 天帆是许多老式方帆船的最上层帆，不过有时上面还会有一面月帆。
- More examples
- Most ship owners considered skysails more ornamental than useful.
- The Portsmouth-built Noonday had only one skysail, on her mainmast.
- Few ships carried skysails in the 1920s.