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fifi hook

British  
/ ˈfiːfiː /

noun

  1. mountaineering a metal hook at the top of an étrier for attaching it to a peg and also connected by a cord to the climber's harness to pull the étrier up and prevent it being dropped

"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

Etymology

Origin of fifi hook

C20: of unknown origin