An Etymological Dictionary of Astronomy and Astrophysics

A curve described by the → polar equation  r² = 4b (a - b sin²θ), where a and b are positive constants. For appropriate
values of a and b, the curve looks like the infinity symbol, ∞. See also → spheres of Eudoxus.

See also: Hippopede, literally “a horse’s foot,” denoting a “horse fetter (hobble),” from Gk. hippos, → horse, + -pede variant of -ped, combining form of pos,→ foot.