Boring

n.
  1. The act or process of one who, or that which, bores; as, the boring of cannon; the boring of piles and ship timbers by certain marine mollusks.
  2. A hole made by boring.
    3. Boring bar ,
    a revolving or stationary bar, carrying one or more cutting tools for dressing round holes.
    Boring tool (Metal Working),
    a cutting tool placed in a cutter head to dress round holes.