No, a counterbore is not a tedious bartender. Although counterbore is sometimes used as a noun, it is more commonly a verb that describes increasing a hole's diameter by drilling a larger-diameter hole at one end to make room for the head of a screw or bolt. In some cases, a counterbored hole is filled with a decorative wood plug to conceal the fastener's head. To countersink a hole is slightly different: this means to drill a shallow hole that will allow a screw's head to sit flush with the surface.To counterbore a hole, it's easiest to drill the larger-diameter hole first, then drill the deeper hole for the fastener's shaft. You should use a spade bit--or better--a Forstner bit that will create a flat-bottomed hole.
It's hard to say where the term counterbore came from. In early 17th century France, counter --or contre--was a fencing term, used to describe a circular parry around the tip of a competitor's sword.
All uses of the word counter seem to have the same reference to opposition...except one: the counter used in a shop (perhaps this type of hole was first used in a bench top).
Bore, a word that both describes a hole and the process of making one, dates back to the early 11th century with roots in many languages, referring to auguring a hole as for a gimlet.
