noun / verb
helmet
HEL-mit/ˈhelmɪt/
A protective covering for the head, or to equip someone with it.
She wears a helmet whenever she rides her bike to work.

Etymology
Helmet may be a diminutive of helm, a protective head-covering; alternatively, it may come from a French diminutive with the same Germanic ancestry. Both explanations connect the word with protection for the head.
In context
wear a helmet when riding a two-wheeler it protects us from injury
More examples
- The firefighter's helmet protects his head from falling debris.
- Players keep their helmets on throughout football practice.
- The guides helmet each visitor before entering the cave.
Forms
helmet · helmets · helmeted · helmeting
Similar words
- hardhat
- Specifically a rigid protective hat worn at work sites.
- headgear
- Includes all head coverings, not just those providing protection.