FOLIUM

folium

(noun) a thin layer or stratum of (especially metamorphic) rock

Source: WordNet® 3.1

Etymology

Noun

folium (plural foliums or folia)

A leaf, especially a thin leaf or plate.

(geometry) A curve of the third order, consisting of two infinite branches having a common asymptote. The curve has a double point, and a leaf-shaped loop.

Source: Wiktionary

Fo"li*um, n.; pl. E. Foliums, L. Folia. Etym: [L., a leaf.]

1. A leaf, esp. a thin leaf or plate.

2. (Geom.)

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition