[1] : The Collaborative International Dictionary of English v.0.48

segmentation \seg`menta"tion\, n.
   the act or process of dividing into segments; specifically
   biol., a self-division into segments as a result of growth;
   cell cleavage; cell multiplication; endogenous cell
   formation.
   1913 webster

   segmentation cavity biol., the cavity formed by the
      arrangement of the cells in segmentation or cleavage of
      the ovum; the cavity of the blastosphere. in the gastrula
      stage, the segmentation cavity in which the mesoblast is
      formed lies between the entoblast and ectoblast. see
      illust. of invagination.

   segmentation nucleus biol., the body formed by fusion of
      the male and female pronucleus in an impregnated ovum. see
      the note under pronucleus.

   segmentation of the ovum, or egg cleavage biol., the
      process by which the embryos of all the higher plants and
      animals are derived from the germ cell. in the simplest
      case, that of small ova destitute of food yolk, the ovum
      or egg divides into two similar halves or segments
      blastomeres, each of these again divides into two, and
      so on, thus giving rise to a mass of cells mulberry mass,
      or morula, all equal and similar, from the growth and
      development of which the future animal is to be formed.
      this constitutes regular segmentation. quite frequently,
      however, the equality and regularity of cleavage is
      interfered with by the presence of food yolk, from which
      results unequal segmentation. see holoblastic,
      meroblastic, alecithal, centrolecithal,
      ectolecithal, and ovum.

   segmentation sphere biol., the blastosphere, or morula.
      see morula.
      1913 webster
see also:
segmentation cavity invagination segmentation nucleus pronucleus segmentation of the ovum egg cleavage 
regular segmentation holoblastic meroblastic alecithal centrolecithal 
ectolecithal ovum segmentation sphere morula 

[2] : The Collaborative International Dictionary of English v.0.48

egg \egg\ e^g, n. oe., fr. icel. egg; akin to as. aeg
   whence oe. ey, sw. aumgg, dan. aeg, g.  d. ei, and
   prob. to oslav. aje, jaje, l. ovum, gr. 'w,o`n, ir. ugh,
   gael. ubh, and perh. to l. avis bird. cf. oval.
   1. popularly the oval or roundish body laid by domestic
      poultry and other birds, tortoises, etc. it consists of a
      yolk, usually surrounded by the "white" or albumen, and
      inclosed in a shell or strong membrane.
      1913 webster

   2. biol. a simple cell, from the development of which the
      young of animals are formed; ovum; germ cell.
      1913 webster

   3. anything resembling an egg in form.
      1913 webster

   note: egg is used adjectively, or as the first part of
         self-explaining compounds; as, egg beater or
         egg-beater, egg case, egg ladle, egg-shaped, etc.
         1913 webster

   egg and anchor arch., see egg-and-dart in the
      vocabulary, below; -- called also egg and dart, and egg
      and tongue. see anchor, n., 5. --ogilvie.

   egg cleavage biol., a process of cleavage or
      segmentation, by which the egg undergoes endogenous
      division with formation of a mass of nearly similar cells,
      from the growth and differentiation of which the new
      organism is ultimately formed. see segmentation of the
      ovum, under segmentation.

   egg development biol., the process of the development of
      an egg, by which the embryo is formed.

   egg mite zo"ol., any mite which devours the eggs of
      insects, as nothrus ovivorus, which destroys those of
      the canker worm.

   egg parasite zo"ol., any small hymenopterous insect,
      which, in the larval stage, lives within the eggs of other
      insects. many genera and species are known.
      1913 webster
see also:
oval egg and anchor egg-and-dart egg and dart egg and tongue anchor 
egg cleavage segmentation of the ovum segmentation egg development egg mite 
nothrus ovivorus egg parasite 

Egg >> E Words
Egg, definition of term: Egg
egg_pag1.html

Cleavage >> C Words
Cleavage, definition of term: Cleavage
cleavage_pag1.html

Egg White >> E Words
Egg White, definition of term: Egg White
egg+white_pag1.html

Easter Egg >> E Words
Easter Egg, definition of term: Easter Egg
easter+egg_pag1.html

Deviled Egg >> D Words
Deviled Egg, definition of term: Deviled Egg
deviled+egg_pag1.html