[1] : The Collaborative International Dictionary of English v.0.48

perpetual \perpet"ual\, a. oe. perpetuel, f. perp'etuel,
   fr. l. perpetualis, fr. perpetuus continuing throughout,
   continuous, fr. perpes, -etis, lasting throughout.
   neverceasing; continuing forever or for an unlimited time;
   unfailing; everlasting; continuous.
   1913 webster

         unto the kingdom of perpetual night.     --shak.
   1913 webster

         perpetual feast of nectared sweets.      --milton.
   1913 webster

   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.
      1913 webster

   syn: continual; unceasing; endless; everlasting; incessant;
        constant; eternal. see constant.
        1913 webster
see also:
circle of perpetual apparition circle of perpetual occultation circle perpetual calendar perpetual curacy perpetual motion 
motion perpetual screw endless screw screw constant 

[2] : The Collaborative International Dictionary of English v.0.48

motion \mo"tion\, n. f., fr. l. motio, fr. movere, motum, to
   move. see move.
   1. the act, process, or state of changing place or position;
      movement; the passing of a body from one place or position
      to another, whether voluntary or involuntary; -- opposed
      to rest.
      1913 webster

            speaking or mute, all comeliness and grace
            attends thee, and each word, each motion, forms.
                                                  --milton.
      1913 webster

   2. power of, or capacity for, motion.
      1913 webster

            devoid of sense and motion.           --milton.
      1913 webster

   3. direction of movement; course; tendency; as, the motion of
      the planets is from west to east.
      1913 webster

            in our proper motion we ascend.       --milton.
      1913 webster

   4. change in the relative position of the parts of anything;
      action of a machine with respect to the relative movement
      of its parts.
      1913 webster

            this is the great wheel to which the clock owes its
            motion.                               --dr. h. more.
      1913 webster

   5. movement of the mind, desires, or passions; mental act, or
      impulse to any action; internal activity.
      1913 webster

            let a good man obey every good motion rising in his
            heart, knowing that every such motion proceeds from
            god.                                  --south.
      1913 webster

   6. a proposal or suggestion looking to action or progress;
      esp., a formal proposal made in a deliberative assembly;
      as, a motion to adjourn.
      1913 webster

            yes, i agree, and thank you for your motion. --shak.
      1913 webster

   7. law an application made to a court or judge orally in
      open court. its object is to obtain an order or rule
      directing some act to be done in favor of the applicant.
      --mozley  w.
      1913 webster

   8. mus. change of pitch in successive sounds, whether in
      the same part or in groups of parts.
      1913 webster

            the independent motions of different parts sounding
            together constitute counterpoint.     --grove.
      1913 webster

   note: conjunct motion is that by single degrees of the scale.
         contrary motion is that when parts move in opposite
         directions. disjunct motion is motion by skips. oblique
         motion is that when one part is stationary while
         another moves. similar or direct motion is that when
         parts move in the same direction.
         1913 webster

   9. a puppet show or puppet. obs.
      1913 webster

            what motion's this? the model of nineveh? --beau. 
                                                  fl.
      1913 webster

   note: motion, in mechanics, may be simple or compound.

   simple motions are: a straight translation, which, if
      of indefinite duration, must be reciprocating. b
      simple rotation, which may be either continuous or
      reciprocating, and when reciprocating is called
      oscillating. c helical, which, if of indefinite
      duration, must be reciprocating.

   compound motion consists of combinations of any of the
      simple motions.
      1913 webster

   center of motion, harmonic motion, etc. see under
      center, harmonic, etc.

   motion block steam engine, a crosshead.

   perpetual motion mech., an incessant motion conceived to
      be attainable by a machine supplying its own motive forces
      independently of any action from without. according to the
      law of conservation of energy, such perpetual motion is
      impossible, and no device has yet been built that is
      capable of perpetual motion.
      1913 webster +pjc

   syn: see movement.
        1913 webster
see also:
move rest simple motions a b c 
compound motion center of motion harmonic motion center harmonic 
motion block perpetual motion movement 

[3] : WordNet (r) 2.0

perpetual motion
     n : motion that continues indefinitely without any external
         source of energy; impossible in practice because of
         friction

Motion >> M Words
Motion, definition of term: Motion
motion_pag1.html

Perpetual >> P Words
Perpetual, definition of term: Perpetual
perpetual_pag1.html

Perpetual Calen >> P Words
Perpetual Calen, definition of term: Perpetual Calen
perpetual+calen_pag1.html

Perpetual Motio >> P Words
Perpetual Motio, definition of term: Perpetual Motio
perpetual+motio_pag1.html

Motion Picture >> M Words
Motion Picture, definition of term: Motion Picture
motion+picture_pag1.html

Motion Sickness >> M Words
Motion Sickness, definition of term: Motion Sickness
motion+sickness_pag1.html

Brownian Motion >> B Words
Brownian Motion, definition of term: Brownian Motion
brownian+motion_pag1.html

Law Of Motion >> L Words
Law Of Motion, definition of term: Law Of Motion
law+of+motion_pag1.html