chalaza

from WordNet (r) 3.0 (2006)

chalaza
    n 1: basal part of a plant ovule opposite the micropyle; where
         integument and nucellus are joined
    2: one of two spiral bands of tissue connecting the egg yolk to
       the enclosing membrane at either end of the shell

from The Collaborative International Dictionary of English v.0.48

Chalaza \Cha*la"za\, n.; pl. E. {Chalazas}, L. {Chalaz[ae]}.
   [NL., fr. Gr. ? hail, pimple.]
   1. (Bot.) The place on an ovule, or seed, where its outer
      coats cohere with each other and the nucleus.
      [1913 Webster]

   2. (Biol.) A spiral band of thickened albuminous substance
      which exists in the white of the bird's egg, and serves to
      maintain the yolk in its position; the treadle.
      [1913 Webster]