PARACENTRIC

Par`a*cen"tric, Par`a*cen"tric*al, a. Etym: [Pref. para- + centric, - ical: cf. F. paracentrique.]

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition