;头盔;防护帽 A helmet is a hat made of a strong material which you wear to protect your head.
Oxford
hel·met/ˈhelmɪt; NAmEˈhelmɪt/noun _cycles_comp.jpg _helmet.jpg a type of hard hat that protects the head, worn, for example, by a police officer, a soldier or a person playing some sports 头盔;防护帽☞see also