countersink

[ verb, noun koun-ter-singk; verb koun-ter-singk ]
/ verb, noun ˈkaʊn tərˌsɪŋk; verb ˌkaʊn tərˈsɪŋk /
SEE SYNONYMS FOR countersink ON THESAURUS.COM

verb (used with object), coun·ter·sank, coun·ter·sunk, coun·ter·sink·ing.

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.

noun

a tool for countersinking a hole.
a countersunk hole.

Origin of countersink

First recorded in 1810–20; counter- + sink

Words nearby countersink

countershading, countershaft, countershock, countersign, countersignature, countersink, counterspy, counterstain, counterstamp, counterstatement, counterstroke

Words related to countersink

auger, punch, implement, bit, gimlet, trephine, trepan, borer, riveter, awl, wimble, corkscrew, jackhammer, dibble

Example sentences from the Web for countersink

British Dictionary definitions for countersink

countersink
/ (ˈkaʊntəˌsɪŋk) /

verb -sinks, -sinking, -sank or -sunk (tr)

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

noun

Also called: countersink bit a tool for countersinking
a countersunk depression or hole