noun, verb ·Rare ·Advanced level

Definitions

Noun

1. 1
   A cylindrical recess, typically machined at the mouth of a hole to admit a screw (such as a cap screw) so that the screw sits flush with a surface.
2. 2
   a bit for enlarging the upper part of a hole wordnet
3. 3
   The cutter used to cut such a recess. (Also used, at less depth, for spotfacing.)

   "Meronyms: flute, pilot (the land at the tip, which rides the hole as a guide), shank"

Verb

1. 1
   To create such a cylindrical recess. transitive

Synonyms

All synonyms

countersinkcountersink bit

Example

More examples

"Meronyms: flute, pilot (the land at the tip, which rides the hole as a guide), shank"

Etymology

From counter- (“against”) + bore (“hole”).

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.