from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A flattened, disklike region of cells from which the embryo begins to develop in the fertilized ovum of many vertebrate species. Also called blastodisk, embryonic disk.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. a small circular white spot on the surface of the yolk of an egg


Sorry, no etymologies found.


Sorry, no example sentences found.

Wordnik is becoming a not-for-profit! Read our announcement here.


Log in or sign up to get involved in the conversation. It's quick and easy.