cleavage

cleavage is a Noun

Definition:

[1] The act of cleaving or splitting.

[2] The quality possessed by many crystallized substances of splitting readily in one or more definite directions, in which the cohesive attraction is a minimum, affording more or less smooth surfaces; the direction of the dividing plane; a fragment obtained by cleaving, as of a diamond. See Parting.

[3] Division into laminæ, like slate, with the lamination not necessarily parallel to the plane of deposition; -- usually produced by pressure. Basal cleavage, cleavage parallel to the base of a crystal, or to the plane of the lateral axes. -- Cell cleavage (Biol.), multiplication of cells by fission. See Segmentation. -- Cubuc cleavage, cleavage parallel to the faces of a cube. -- Diagonal cleavage, cleavage parallel to ta diagonal plane. -- Egg clavage. (Biol.) See Segmentation. -- Lateral cleavage, cleavage parallel to the lateral planes. -- Octahedral, Dodecahedral, or Rhombohedral, cleavage, cleavage parallel to the faces of an octahedron, dodecahedron, or rhombohedron. -- Prismatic cleavage, cleavage parallel to a vertical prism.