Word.ws English Dictionary

countersink

countersink noun: a conical recess, typically machined at the mouth of a hole to admit a screw (with a matching taper) so that the screw sits flush with a surface.

countersink: a conical recess, typically machined at the mouth of a hole to admit a screw (with a matching...
Image: Waerloeg, CC0, via Wikimedia Commons

Noun

countersink (plural countersinks)

  1. A conical recess, typically machined at the mouth of a hole to admit a screw (with a matching taper) so that the screw sits flush with a surface.
  2. The cutter used to cut such a recess. (Also used, at less depth, for edge-breaking/deburring.)
    • Holonym: center drill (combined drill and countersink)
    Synonyms:
    countersinker

Verb

countersink (third-person singular simple present countersinks, present participle countersinking, simple past countersank or countersunk, past participle countersunk)

  1. (transitive) To create such a conical recess.
    • to countersink a hole for a screw
  2. (ambitransitive) To cause to sink even with or below the surface.
    • to countersink a screw or bolt into woodwork
    • I countersank into the locust just enough to make the nailhead flush.2010, Larry Pardey, Details of Classic Boat Construction, pages 7-30

Synonyms of countersink

Forms of countersink

Noun
pluralcountersinks
Verb
third-person singular presentcountersinks
present participlecountersinking
pastcountersank
pastcountersunk
past participlecountersunk

Origin of countersink

From counter- + sink.

Words formed from countersink

Questions about countersink

What does countersink mean?
Countersink means a conical recess, typically machined at the mouth of a hole to admit a screw (with a matching taper) so that the screw sits flush with a surface.
What part of speech is countersink?
Countersink can be a noun or a verb.
What is the plural of countersink?
The plural of countersink is countersinks.

Words near countersink in the dictionary

  1. countersigning
  2. countersigns
  3. countersing
  4. countersinging
  5. countersings
  6. countersink
  7. countersinker
  8. countersinkers
  9. countersinking
  10. countersinks
  11. counterslogan

Source and license

Adapted from Wiktionary: countersink (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Pronunciation audio from Wikimedia Commons, each file under its own free license: LL-Q1860 (eng)-Flame, not lame-countersink.wav.

Cite this entry: “countersink.” Word.ws, https://word.ws/countersink. Based on Wiktionary, CC BY-SA 4.0.