counterbore

[ koun-ter-bawr, -bohr; koun-ter-bawr, -bohr ]
/ ˈkaʊn tərˌbɔr, -ˌboʊr; ˈkaʊn tərˈbɔr, -ˈboʊr /

noun

a tool for enlarging a drilled hole for a portion of its length, as to permit sinking a screw head.
the portion of the hole so enlarged.

verb (used with object), coun·ter·bored, coun·ter·bor·ing.

to enlarge (a drilled hole) along part of the length of the hole by drilling with a bit having a greater diameter.

QUIZZES

BEAT THE DOLDRUMS WITH THIS WORD OF THE DAY QUIZ!

We know you’ll tackle this quiz totis viribus! See how many words from the week of Oct 12–18, 2020 you get right!
Question 1 of 7
What does “Indigenous” mean?

Origin of counterbore

First recorded in 1605–15; counter- + bore2

OTHER WORDS FROM counterbore

coun·ter·bor·er, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for counterbore