- (n.) A drill or cutting tool for countersinking holes.
- (n.) An enlargement of the upper part of a hole, forming a cavity or depression for receiving the head of a screw or bolt.
- (v.t.) 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 screw.
- (v.t.) To cause to sink even with or below the surface; as, to countersink a screw or bolt into woodwork.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). countersink. Retrieved September 21, 2026, from http://smartdefine.org/countersink/definitions/1992286 |
| Chicago | Webster's. 2011. "countersink" http://smartdefine.org/countersink/definitions/1992286 (accessed September 21, 2026). |
| Harvard | Webster's 2011, countersink, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/countersink/definitions/1992286>. |
| MLA | Webster's. "countersink" 27 May 2011. Web. 21 September 2026. <http://smartdefine.org/countersink/definitions/1992286> |