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

pendulum \pen"dulum\, n.; pl. pendulums. nl., fr. l.
   pendulus hanging, swinging. see pendulous.
   a body so suspended from a fixed point as to swing freely to
   and fro by the alternate action of gravity and momentum. it
   is used to regulate the movements of clockwork and other
   machinery.
   1913 webster

   note: the time of oscillation of a pendulum is independent of
         the arc of vibration, provided this arc be small.
         1913 webster

   ballistic pendulum. see under ballistic.

   compensation pendulum, a clock pendulum in which the effect
      of changes of temperature of the length of the rod is so
      counteracted, usually by the opposite expansion of
      differene metals, that the distance of the center of
      oscillation from the center of suspension remains
      invariable; as, the mercurial compensation pendulum, in
      which the expansion of the rod is compensated by the
      opposite expansion of mercury in a jar constituting the
      bob; the gridiron pendulum, in which compensation is
      effected by the opposite expansion of sets of rods of
      different metals.

   compound pendulum, an ordinary pendulum; -- so called, as
      being made up of different parts, and contrasted with
      simple pendulum.

   conical pendulum or revolving pendulum, a weight
      connected by a rod with a fixed point; and revolving in a
      horizontal circle about the vertical from that point.

   pendulum bob, the weight at the lower end of a pendulum.

   pendulum level, a plumb level. see under level.

   pendulum wheel, the balance of a watch.

   simple pendulum or theoretical pendulum, an imaginary
      pendulum having no dimensions except length, and no weight
      except at the center of oscillation; in other words, a
      material point suspended by an ideal line.
      1913 webster
see also:
pendulums pendulous ballistic pendulum ballistic compensation pendulum mercurial compensation pendulum 
gridiron pendulum compound pendulum simple pendulum conical pendulum revolving pendulum 
pendulum bob pendulum level level pendulum wheel simple pendulum 
theoretical pendulum 

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

ballistic \ballis"tic\, a.
   1. of or pertaining to the ballista, or to the art of hurling
      stones or missile weapons by means of an engine.
      1913 webster

   2. pertaining to ballistics2, or to a projectile in a
      gravitational field.
      1913 webster +pjc

   3. frenzied; very angry; -- used mostly in the phrase

   go ballistic. colloq.
      pjc

   ballistic pendulum, an instrument consisting of a mass of
      wood or other material suspended as a pendulum, for
      measuring the force and velocity of projectiles by means
      of the arc through which their impact impels it.
      1913 webster
see also:
go ballistic ballistic pendulum 

[3] : WordNet (r) 2.0

ballistic pendulum
     n : a physical pendulum consisting of a large mass suspended
         from a rod; its displacement is used to measure the
         velocity of a projectile

Pendulum >> P Words
Pendulum, definition of term: Pendulum
pendulum_pag1.html

Ballistic >> B Words
Ballistic, definition of term: Ballistic
ballistic_pag1.html

Pendulum Clock >> P Words
Pendulum Clock, definition of term: Pendulum Clock
pendulum+clock_pag1.html

Ballistic Pendu >> B Words
Ballistic Pendu, definition of term: Ballistic Pendu
ballistic+pendu_pag1.html

Ballistic Missi >> B Words
Ballistic Missi, definition of term: Ballistic Missi
ballistic+missi_pag1.html