noun, plural blas·tu·las, blas·tu·lae [blas-chuh-lee] /ˈblæs tʃəˌli/. Embryology.
  1. the early developmental stage of an animal, following the morula stage and consisting of a single, spherical layer of cells enclosing a hollow, central cavity.
Compare blastocyst.

Origin of blastula

1885–90; < New Latin < Greek blast(ós) bud, sprout + New Latin -ula -ule
Related formsblas·tu·lar, adjectiveblas·tu·la·tion [blas-chuh-ley-shuh n] /ˌblæs tʃəˈleɪ ʃən/, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for blastulation


  1. embryol the process of blastula formation


noun plural -las or -lae (-liː)
  1. an early form of an animal embryo that develops from a morula, consisting of a sphere of cells with a central cavityAlso called: blastosphere
Derived Formsblastular, adjective

Word Origin for blastula

C19: New Latin; see blasto-
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for blastulation



embryonic state, 1875, Modern Latin, from Greek blastos "sprout, germ" + diminutive ending -ula.

Online Etymology Dictionary, © 2010 Douglas Harper

blastulation in Medicine


n. pl. blas•tu•las
  1. An early embryonic form produced by cleavage of a fertilized ovum and consisting of a spherical layer of cells surrounding a fluid-filled cavity.
Related formsblastu•lar adj.blas′tu•lation (-lāshən) n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

blastulation in Science


Plural blastulas blastulae (blăschə-lē′)
  1. An animal embryo at the stage immediately following the division of the fertilized egg cell, consisting of a ball-shaped layer of cells around a fluid-filled cavity known as a blastocoel. Compare gastrula. See also blastocyst.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

blastulation in Culture



The stage of an embryo that consists of just over a hundred cells — a stage reached about one week after fertilization. At this stage the cells are just at the very beginning of cellular differentiation and are said to be totipotent (See totipotency).


This is the stage of development where embryonic stems cells can be harvested for medical research.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.