Found 2 items, similar to counterbore.
English → English (WordNet) Definition: counterbore counterbore n : a bit for enlarging the upper part of a hole [syn: countersink, countersink bit]
English → English (gcide) Definition: Counterbore Counterbore \Coun"ter*bore`\ (-b?r`), n. 1. A flat-bottomed cylindrical enlargement of the mouth of a hole, usually of slight depth, as for receiving a cylindrical screw head. [1913 Webster] 2. A kind of pin drill with the cutting edge or edges normal to the axis; -- used for enlarging a hole, or for forming a flat-bottomed recess at its mouth. [1913 Webster] Counterbore \Coun`ter*bore"\ (koun`t?r-b?r"), v. t. To form a counterbore in, by boring, turning, or drilling; to enlarge, as a hole, by means of a counterbore. [1913 Webster]