Ripcord (noun)

1. A cord that is pulled to release a device such as a parachute or emergency brake.
2. A cord or handle that, when pulled, initiates a mechanical or electrical action.

Origin:

1940s: from rip (from the verb rip meaning "tear off") + cord.

Examples:

1. The skydiver pulled the ripcord to deploy his parachute.
2. The ripcord is used to activate the emergency brake on the roller coaster.
3. The pilot pulled the ripcord to deploy the emergency ejection seat.
4. The ripcord is an important safety feature on the parachute.
5. The ripcord is located on the handle of the parachute, and can be pulled easily in case of emergency.