Definify.com
Webster 1913 Edition
Countersink
Coun′ter-sinkˊ
(koun′tẽr-sĭṉkˊ; 277)
, Verb.
T.
[
imp. & p. p.
Countersunk
(-sŭṉkˊ)
; p. pr. & vb. n.
Countersinking
.] 1.
To chamfer or form a depression around the top of (a hole in wood, metal, etc.) for the reception of the head of a screw or bolt below the surface, either wholly or in part;
as, to
. countersink
a hole for a screw2.
To cause to sink even with or below the surface;
as, to
. countersink
a screw or bolt into woodworkCoun′ter-sinkˊ
,Noun.
1.
An enlargement of the upper part of a hole, forming a cavity or depression for receiving the head of a screw or bolt.
☞ In the United States a flaring cavity formed by chamfering the edges of a round hole is called a countersink, while a cylindrical flat-bottomed enlargement of the mouth of the hole is usually called
a conterbore
. 2.
A drill or cutting tool for countersinking holes.