双纽线
Lemniscata \Lem`nis*ca"ta\ (l[e^]m`n[i^]s*k[=a]"t[.a]), Lemniscate \Lem*nis"cate\ (l[e^]m*n[i^]s"k[asl]t), n. [L. lemniscatus adorned with ribbons, fr. lemniscus a ribbon hanging down, Gr. lhmni`skos.] (Geom.) 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.