a D-shaped ring with a spring catch on one side, used for fastening ropes in mountaineering.
Origin of carabiner
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for carabiner
The carabiner is a D-shaped metal clamp that has a gate that opens and closes.Thrills and Too Many Spills: The Dangers of the Circus|Marina Watts|May 5, 2014|DAILY BEAST
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012