The Collaborative International Dictionary of English v.0.48:

Voltaic \Vol*ta"ic\, a. [Cf. F. volta["i]que, It. voltaico.]
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   1. Of or pertaining to Alessandro Volta, who first devised
      apparatus for developing electric currents by chemical
      action, and established this branch of electric science;
      discovered by Volta; as, voltaic electricity.
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   2. Of or pertaining to voltaism, or voltaic electricity; as,
      voltaic induction; the voltaic arc.
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   Note: See the Note under Galvanism.
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   Voltaic arc, a luminous arc, of intense brilliancy, formed
      between carbon points as electrodes by the passage of a
      powerful voltaic current.

   Voltaic battery, an apparatus variously constructed,
      consisting of a series of plates or pieces of dissimilar
      metals, as copper and zinc, arranged in pairs, and
      subjected to the action of a saline or acid solution, by
      which a current of electricity is generated whenever the
      two poles, or ends of the series, are connected by a
      conductor; a galvanic battery. See Battery, 4.
      (b), and Note.

   Voltaic circuit. See under Circuit.

   Voltaic couple or Voltaic element, a single pair of the
      connected plates of a battery.

   Voltaic electricity. See the Note under Electricity.

   Voltaic pile, a kind of voltaic battery consisting of
      alternate disks of dissimilar metals, separated by
      moistened cloth or paper. See 5th Pile.

   Voltaic protection of metals, the protection of a metal
      exposed to the corrosive action of sea water, saline or
      acid liquids, or the like, by associating it with a metal
      which is positive to it, as when iron is galvanized, or
      coated with zinc.
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The Collaborative International Dictionary of English v.0.48:

Arc \Arc\, n. [F. arc, L. arcus bow, arc. See Arch, n.]
   1. (Geom.) A portion of a curved line; as, the arc of a
      circle or of an ellipse.
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   2. A curvature in the shape of a circular arc or an arch; as,
      the colored arc (the rainbow); the arc of Hadley's
      quadrant.
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   3. An arch. [Obs.]
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            Statues and trophies, and triumphal arcs. --Milton.
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   4. The apparent arc described, above or below the horizon, by
      the sun or other celestial body. The diurnal arc is
      described during the daytime, the nocturnal arc during the
      night.
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   Electric arc, Voltaic arc. See under Voltaic.
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