folium

Fo"li*um, n.; pl. E. Foliums, L. Folia. Etym: [L., a leaf.] 1. A leaf, esp. a thin leaf or plate. 2. (Geom.) Defn: A curve of the third order, consisting of two infinite branches, which have a common asymptote. The curve has a double point, and a leaf-shaped loop; whence the name. Its equation is x3 + y3 = axy.

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