[verb, noun koun-ter-singk; verb koun-ter-singk]
- to enlarge the upper part of (a cavity), especially by chamfering, to receive the cone-shaped head of a screw, bolt, etc.
- to cause (the head of a screw, bolt, etc.) to sink into a prepared depression so as to be flush with or below the surface.
- a tool for countersinking a hole.
- a countersunk hole.
Origin of countersink
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- to enlarge the upper part of (a hole) in timber, metal, etc, so that the head of a bolt or screw can be sunk below the surface
- to drive (a screw) or sink (a bolt) into such an enlarged hole
- Also called: countersink bit a tool for countersinking
- a countersunk depression or hole
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