countersink

[ verb noun koun-ter-singk; verb koun-ter-singk ]

verb (used with object)

, coun·ter·sank, coun·ter·sunk, coun·ter·sink·ing.

1. to enlarge the upper part of (a cavity), especially by chamfering, to receive the cone-shaped head of a screw, bolt, etc.
2. 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

1. a tool for countersinking a hole.
2. a countersunk hole.

countersink

/ ˈkaʊntəˌsɪŋk /

verb

1. 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
2. to drive (a screw) or sink (a bolt) into such an enlarged hole

noun

1. Also calledcountersink bit a tool for countersinking
2. a countersunk depression or hole

Word History and Origins

Origin of countersink¹

First recorded in 1810–20; counter- + sink

Example Sentences

The round-headed screws are best, unless you want to countersink them.

From Project Gutenberg

Countersink for the heads on the back of the shield and so fasten the antlers in place.

From Project Gutenberg

Bore all holes, where shown in the drawing, and countersink them.

From Project Gutenberg

Countersink the holes on the side from which the screws enter.

From Project Gutenberg

Countersink all holes, except the four holes which hold the supports for the cart handle.

From Project Gutenberg