\Par`a*bol"ic\, Parabolical \Par`a*bol"ic*al\, a. [Gr.
paraboliko`s figurative: cf. F. parabolique. See {Parable}.]
1. Of the nature of a parable; expressed by a parable or
   figure; allegorical; as, parabolical instruction.
2. [From {Parabola}.] (Geom.)
   (a) Having the form or nature of a parabola; pertaining
       to, or resembling, a parabola; as, a parabolic curve.
   (b) Generated by the revolution of a parabola, or by a
       line that moves on a parabola as a directing curve;
       as, a parabolic conoid.
{Parabolic conoid}, a paraboloid; a conoid whose directing
   curve is a parabola. See {Conoid}.
{Parabolic mirror} (Opt.), a mirror having a paraboloidal
   surface which gives for parallel rays (as those from very
   distant objects) images free from aberration. It is used
   in reflecting telescopes.
{Parabolic spindle}, the solid generated by revolving the
   portion of a parabola cut off by a line drawn at right
   angles to the axis of the curve, about that line as an
   axis.
{Parabolic spiral}, a spiral curve conceived to be formed by
   the periphery of a semiparabola when its axis is wrapped
   about a circle; also, any other spiral curve having an
   analogy to the parabola.