yolk-sac placenta


Definition of yolk-sac placenta

: a structure in some sharks resembling a placenta, consisting of the vascular embryonic yolk sac wall intimately associated with the vascular maternal uterine or oviducal wall, and serving to nourish the embryo

Love words?

You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.

Start your free trial today and get unlimited access to America's largest dictionary, with:

  • More than 250,000 words that aren't in our free dictionary
  • Expanded definitions, etymologies, and usage notes
  • Advanced search features
  • Ad free!

Learn More about yolk-sac placenta

Statistics for yolk-sac placenta

Cite this Entry

“Yolk-sac placenta.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/yolk-sac%20placenta. Accessed 10 Aug. 2020.

Comments on yolk-sac placenta

What made you want to look up yolk-sac placenta? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Original Meanings Quiz

  • rembrandt painting a young scholar and his tutor
  • Which of the following is the earliest known sense of the word awe?
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!