The Collaborative International Dictionary of English v.0.48:

Emery \Em"er*y\, n. [F. ['e]meri, earlier ['e]meril, It.
   smeriglio, fr. Gr. ?, ?, ?, cf. ? to wipe; perh. akin to E.
   smear. Cf. Emeril.] (Min.)
   Corundum in the form of grains or powder, used in the arts
   for grinding and polishing hard substances. Native emery is
   mixed with more or less magnetic iron. See the Note under
   Corundum.
   [1913 Webster]

   Emery board, cardboard pulp mixed with emery and molded
      into convenient.

   Emery cloth or Emery paper, cloth or paper on which the
      powder of emery is spread and glued for scouring and
      polishing.

   Emery wheel, a wheel containing emery, or having a surface
      of emery. In machine shops, it is sometimes called a buff
      wheel, and by the manufacturers of cutlery, a glazer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

emery wheel
    n 1: a wheel composed of abrasive material; used for grinding
         [syn: grinding wheel, emery wheel]