Source : Webster's Revised Unabridged Dictionary (1913)

Dollar \Dol"lar\, n. [D. daalder, LG. dahler, G. thaler, an
   abbreviation of Joachimsthaler, i. e., a piece of money first
   coined, about the year 1518, in the valley (G. thal) of St.
   Joachim, in Bohemia. See {Dale}.]
   1.
      (a) A silver coin of the United States containing 371.25
          grains of silver and 41.25 grains of alloy, that is,
          having a total weight of 412.5 grains.
      (b) A gold coin of the United States containing 23.22
          grains of gold and 2.58 grains of alloy, that is,
          having a total weight of 25.8 grains, nine-tenths
          fine. It is no longer coined.

   Note: Previous to 1837 the silver dollar had a larger amount
         of alloy, but only the same amount of silver as now,
         the total weight being 416 grains. The gold dollar as a
         distinct coin was first made in 1849. The eagles, half
         eagles, and quarter eagles coined before 1834 contained
         24.75 grains of gold and 2.25 grains of alloy for each
         dollar.

   2. A coin of the same general weight and value, though
      differing slightly in different countries, current in
      Mexico, Canada, parts of South America, also in Spain, and
      several other European countries.

   3. The value of a dollar; the unit commonly employed in the
      United States in reckoning money values.

   {Chop dollar}. See under 9th {Chop}.

   {Dollar fish} (Zo["o]l.), a fish of the United States coast
      ({Stromateus triacanthus}), having a flat, roundish form
      and a bright silvery luster; -- called also {butterfish},
      and {Lafayette}. See {Butterfish}.

   {Trade dollar}, a silver coin formerly made at the United
      States mint, intended for export, and not legal tender at
      home. It contained 378 grains of silver and 42 grains of
      alloy.

Butterfish \But"ter*fish`\, n. (Zo["o]l.)
   A name given to several different fishes, in allusion to
   their slippery coating of mucus, as the {Stromateus
   triacanthus} of the Atlantic coast, the {Epinephelus
   punctatus} of the southern coast, the rock eel, and the
   kelpfish of New Zealand.