oilstone

from WordNet (r) 3.0 (2006)

oilstone
    n 1: a whetstone for use with oil

from The Collaborative International Dictionary of English v.0.48

Oilstone \Oil"stone`\, n.
   A variety of hone slate, or whetstone, used for whetting
   tools when lubricated with oil.
   [1913 Webster]

from The Collaborative International Dictionary of English v.0.48

Whet \Whet\, n.
   [1913 Webster]
   1. The act of whetting.
      [1913 Webster]

   2. That which whets or sharpens; esp., an appetizer. "Sips,
      drams, and whets." --Spectator.
      [1913 Webster]

   {Whet slate} (Min.), a variety of slate used for sharpening
      cutting instruments; novaculite; -- called also {whetstone
      slate}, and {oilstone}.
      [1913 Webster]