Webster's Revised Unabridged Dictionary · 1913

Lemniscata

Lemniscata (lem`nis*kā"tȧ) , noun

[Latin lemniscatus adorned with ribbons, from lemniscus a ribbon hanging down, Greek lhmni`skos.]

(Geometry) A curve in the form of the figure 8, with both parts symmetrical, generated by the point in which a tangent to an equilateral hyperbola meets the perpendicular on it drawn from the center.

Also: Lemniscate