Definition of "conic section" [conic section]

• The intersection of a right circular cone and a plane, which generates one of a group of plane curves, including the circle, ellipse, hyperbola, and parabola. (noun)
• A graph of the general quadratic equation in two variables. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In the latter end of the third year, my uncle Toby perceiving that the parameter and semi-parameter of the conic section angered his wound, he left off the study of projectiles in a kind of a huff, and betook himself to the practical part of fortification only; the pleasure of which, like a spring held back, returned upon him with redoubled force."