carabiner
nounUK /ˌkærəˈbiːnə/
US /ˌkærəˈbiːnər/
A carabiner is a metal ring with a clip that opens and closes to hold things safely.
She clipped her water bottle to her backpack with a carabiner.
OTHER MEANINGS
2. A strong metal loop used by climbers to attach ropes to their harness.
The climber checked his carabiner before starting the climb.
3. A small clip used to hold keys or tools together.
He kept his keys on a carabiner so they wouldn't get lost.
4. A piece of gear used in rescue work to connect ropes and equipment.
The rescue team used a carabiner to secure the safety line.