1. (noun) a bit for enlarging the upper part of a hole

• counterbore
• countersink bit

2. (verb) insert (a nail or screw below the surface, as into a countersink)

• set

1. (noun) a hole (usually in wood) with the top part enlarged so that a screw or bolt will fit into it and lie below the surface

• hole

2. (noun) a bit for enlarging the upper part of a hole

• bit

3. (verb) insert (a nail or screw below the surface, as into a countersink)

• bury
• sink

1. (noun) a hole (usually in wood) with the top part enlarged so that a screw or bolt will fit into it and lie below the surface

• set