\Pa*rab"o*la\, n.; pl. {Parabolas}. [NL., fr. Gr. ?; --
so called because its axis is parallel to the side of the
cone. See {Parable}, and cf. {Parabole}.] (Geom.)
(a) A kind of curve; one of the conic sections formed by the
    intersection of the surface of a cone with a plane
    parallel to one of its sides. It is a curve, any point of
    which is equally distant from a fixed point, called the
    focus, and a fixed straight line, called the directrix.
    See {Focus}.
(b) One of a group of curves defined by the equation y =
    ax^{n} where n is a positive whole number or a positive
    fraction. For the {cubical parabola} n = 3; for the
    {semicubical parabola} n = 3/2. See under {Cubical}, and
    {Semicubical}. The parabolas have infinite branches, but
    no rectilineal asymptotes.