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.
noun. a bit for enlarging the upper part of a hole.
- countersink bit
verb. insert (a nail or screw below the surface, as into a countersink).
Example sentences of the word countersink
1. Noun, singular or mass
Insert a countersink drill bit into the drill and hold the drill in line with the rivet hole.
2. Verb, base form
Hold the drill steady and straight and do not countersink too deep.