The Collaborative International Dictionary of English v.0.48:

Perpetual \Per*pet"u*al\, a. [OE. perpetuel, F. perp['e]tuel,
   fr. L. perpetualis, fr. perpetuus continuing throughout,
   continuous, fr. perpes, -etis, lasting throughout.]
   Neverceasing; continuing forever or for an unlimited time;
   unfailing; everlasting; continuous.
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         Unto the kingdom of perpetual night.     --Shak.
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         Perpetual feast of nectared sweets.      --Milton.
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   Circle of perpetual apparition, or Circle of perpetual
   occultation. See under Circle.

   Perpetual calendar, a calendar so devised that it may be
      adjusted for any month or year.

   Perpetual curacy (Ch. of Eng.), a curacy in which all the
      tithes are appropriated, and no vicarage is endowed.
      --Blackstone.

   Perpetual motion. See under Motion.

   Perpetual screw. See Endless screw, under Screw.
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   Syn: Continual; unceasing; endless; everlasting; incessant;
        constant; eternal. See Constant.
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