Meaning of COUNTERBORE in English

COUNTERBORE

— counterborer , n.

/kown"teuhr bawr', -bohr'; kown"teuhr bawr", -bohr"/ , n. , v. , counterbored, counterboring .

n.

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

2. the portion of the hole so enlarged.

v.t.

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

[ 1605-15; COUNTER- + BORE 1 ]

Random House Webster's Unabridged English dictionary.      Полный английский словарь Вебстер - Random House .