Source : Webster's Revised Unabridged Dictionary (1913)

Clog \Clog\, n. [OE. clogge clog, Scot. clag, n., a clot, v., to
   to obstruct, cover with mud or anything adhesive; prob. of
   the same origin as E. clay.]
   1. That which hinders or impedes motion; hence, an
      encumbrance, restraint, or impediment, of any kind.

            All the ancient, honest, juridical principles and
            institutions of England are so many clogs to check
            and retard the headlong course of violence and
            opression.                            --Burke.

   2. A weight, as a log or block of wood, attached to a man or
      an animal to hinder motion.

            As a dog . . . but chance breaks loose, And quits
            his clog.                             --Hudibras.

            A clog of lead was round my feet.     --Tennyson.

   3. A shoe, or sandal, intended to protect the feet from wet,
      or to increase the apparent stature, and having,
      therefore, a very thick sole. Cf. {Chopine}.

            In France the peasantry goes barefoot; and the
            middle sort . . . makes use of wooden clogs.
                                                  --Harvey.

   {Clog almanac}, a primitive kind of almanac or calendar,
      formerly used in England, made by cutting notches and
      figures on the four edges of a clog, or square piece of
      wood, brass, or bone; -- called also a {Runic staff}, from
      the Runic characters used in the numerical notation.

   {Clog dance}, a dance performed by a person wearing clogs, or
      thick-soled shoes.

   {Clog dancer}.

Source : WordNet®

clog dancer
     n : someone who does clog dancing