Source : Webster's Revised Unabridged Dictionary (1913)

Paracentric \Par`a*cen"tric\, Paracentrical \Par`a*cen"tric*al\,
   a. [Pref. para- + centric, -ical: cf. F. paracentrique.]
   Deviating from circularity; changing the distance from a
   center.

   {Paracentric curve} (Math.), a curve having the property
      that, when its plane is placed vertically, a body
      descending along it, by the force of gravity, will
      approach to, or recede from, a fixed point or center, by
      equal distances in equal times; -- called also a
      {paracentric}.

   {Paracentric motton} or {velocity}, the motion or velocity of
      a revolving body, as a planet, by which it approaches to,
      or recedes from, the center, without reference to its
      motion in space, or to its motion as reckoned in any other
      direction.