chinstrap
/ˈtʃɪnstrap
/noun
A strap attached to a hat, helmet, or other headgear, designed to hold it in place by fitting under the wearer’s chin.Sweat drips from the helmet chinstraps of the engineers who have fitted the demolition charges to the house's steel doors....
- A loose chinstrap allows a helmet to flop around, and thereby leaves you, the user, susceptible to injury in the event of a crash.
- After the ball falls to the grass, Couch angrily unsnaps the chinstrap on his helmet and looks down.