folium

[foh-lee-uh m] /ˈfoʊ li əm/
noun, plural folia
[foh-lee-uh] /ˈfoʊ li ə/ (Show IPA)
1.
a thin leaflike stratum or layer; a lamella.
2.
Geometry. a loop; part of a curve terminated at both ends by the same node. Equation: x 3 + y 3 = 3 axy.
Origin
1840-50; < Neo-Latin, Latin: literally, a leaf
British Dictionary definitions for folium

folium

/ˈfəʊlɪəm/
noun (pl) -lia (-lɪə)
1.
a plane geometrical curve consisting of a loop whose two ends, intersecting at a node, are asymptotic to the same line. Standard equation: x³ + y³=3axy where x=y+a is the equation of the line
2.
any thin leaflike layer, esp of some metamorphic rocks
Word Origin
C19: from Latin, literally: leaf
Word Origin and History for folium
n.

see folio.

folium in Medicine

folium fo·li·um (fō'lē-əm)
n. pl. fo·li·a (-lē-ə)
A broad, thin, leaflike structure, as of the cerebellar cortex.

folium in Science
folium
  (fō'lē-əm)   
Plural folia

  1. A thin, leaflike layer or stratum occurring especially in metamorphic rock.

  2. A plane cubic curve having a single loop, a node, and two ends asymptotic to the same line. Also called folium of Descartes.