D defs.my
Entry 1 sense Webster, 1913

Parabola

/pẽr-ăb'-əl-ə/ · Pa·rab·o·la · IPA /pəˈɹæbələ/
01 n. 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. …
pl. Parabolas ((#))
  1. 1.
    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.(Geom.) See: Focus