A "crash helmet" is a protective headgear worn by people when they are riding a motorcycle, bicycle, or engaging in certain dangerous sports. It is designed to protect the head and reduce the risk of injury during accidents or falls. Full definition
Options include a few goodies specifically tailored for those who own crash helmets, like racing bucket seats composed of pure carbon fiber. (topspeed.com)
Bikers wear crash helmets for their own safety, but they are required to take them off in banks and shops. (conservativehome.blogs.com)
Listening to these claims reminds me of Annie Dillard saying that we should wear crash helmets when sitting in the pew (Teaching a Stone to Talk). (religion-online.org)