The Collaborative International Dictionary of English v.0.48:

Auger \Au"ger\, n. [OE. augoure, nauger, AS. nafeg[=a]r, fr.
   nafu, nafa, nave of a wheel + g[=a]r spear, and therefore
   meaning properly and originally a nave-bore. See Nave (of a
   wheel) and 2d Gore, n.]
   1. A carpenter's tool for boring holes larger than those
      bored by a gimlet. It has a handle placed crosswise by
      which it is turned with both hands. A pod auger is one
      with a straight channel or groove, like the half of a bean
      pod. A screw auger has a twisted blade, by the spiral
      groove of which the chips are discharge.
      [1913 Webster]

   2. An instrument for boring or perforating soils or rocks,
      for determining the quality of soils, or the nature of the
      rocks or strata upon which they lie, and for obtaining
      water.
      [1913 Webster]

   Auger bit, a bit with a cutting edge or blade like that of
      an anger.
      [1913 Webster]