Source : Webster's Revised Unabridged Dictionary (1913)

Foliation \Fo"li*a"tion\, n. [Cf. F. foliation.]
   1. The process of forming into a leaf or leaves.

   2. The manner in which the young leaves are dispo?ed within
      the bud.

            The . . . foliation must be in relation to the stem.
                                                  --De Quincey.

   3. The act of beating a metal into a thin plate, leaf, foil,
      or lamina.

   4. The act of coating with an amalgam of tin foil and
      quicksilver, as in making looking-glasses.

   5. (Arch.) The enrichment of an opening by means of foils,
      arranged in trefoils, quatrefoils, etc.; also, one of the
      ornaments. See {Tracery}.

   6. (Geol.) The property, possessed by some crystalline rocks,
      of dividing into plates or slabs, which is due to the
      cleavage structure of one of the constituents, as mica or
      hornblende. It may sometimes include slaty structure or
      cleavage, though the latter is usually independent of any
      mineral constituent, and transverse to the bedding, it
      having been produced by pressure.

Source : WordNet®

foliation
     n 1: (botany) the process of forming leaves [syn: {leafing}]
     2: (geology) the arrangement of leaflike layers in a rock
     3: (architecture) leaf-like architectural ornament [syn: {foliage}]
     4: the production of foil by cutting or beating metal into thin
        leaves
     5: the work of coating glass with metal foil