Chinstrap (noun)

A strap or band that is fastened under the chin to hold a hat or helmet in place.

Origin:

Early 19th century. from chin + strap.

Examples:

1. The football player wore a helmet with a chinstrap.
2. The chinstrap kept the hat from flying off in the wind.
3. The chinstrap was adjusted to fit the player's chin.
4. The chinstrap was made of durable material that wouldn't break easily.
5. The chinstrap was an important safety feature for the helmet.