Emily Dickinson Lexicon

HY-PER'BO-LA, n. [Gr. υπερ, over, beyond, and βαλλω, to throw.]

In conic sections and geometry, a curve formed by cutting a cone in a direction parallel to its axis. Encyc. A section of a cone, when the cutting plane makes a greater angle with the base than the side of the cone makes. Webber. The latter definition is the most correct.