countersink bit countersink • countersleight · · · Info · Definitions · Synonyms · Characters · · countersink bit · · Text Common · · Latin · · Scripts 15 · · Length 4 · · Syllables Definitions · · · (noun) a bit for enlarging the upper part of a hole. Synonyms: counterbore, countersink, countersink bit. · · Noun Definition 1 Synonyms · · · counterbore · · Synonym 1 countersink · · Synonym 2 Characters · · space U+0020 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 i latin small letter i U+0069 k latin small letter k U+006B n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 u latin small letter u U+0075