from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity. Also called blastosphere.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. An early form in the development of an embryo, consisting of a spherical layer of cells filled with fluid; a blastosphere.
from the GNU version of the Collaborative International Dictionary of English
- n. That stage in the development of the ovum in which the outer cells of the morula become more defined and form the blastoderm.
from The Century Dictionary and Cyclopedia
- n. In embryology: An embryo of one of the Metazoa, in the stage in which it consists of a sac formed of a single layer of cells.
- n. In Haeckel′ s vocabulary of embryology, same as blastosphere, .
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs
New Latin : from Greek blastos, bud + Latin -ula, feminine diminutive suffix.(American Heritage® Dictionary of the English Language, Fourth Edition)
From New Latin, diminutive of Ancient Greek βλαστός (blastos, "a germ, bud, sprout, shoot"), from βλαστάνειν (blastanein, "to bud, sprout, grow, properly of plants, but also of animals"). (Wiktionary)