(Geometry) A curve generated by the intersection of a plane and a circular cone; SYN. conic.
Curve obtained when a conical surface is intersected by a plane. If the intersecting plane cuts both extensions of the cone, it yields a hyperbola; if it is parallel to the side of the cone, it produces a parabola. Other intersecting planes produce circles or ellipses.
The Greek mathematician Apollonius wrote eight books with the title Conic Sections, which superseded previous work on the subject by Aristarchus and Euclid.