su·​per·​fe·​ta·​tion | \ ˌsü-pər-fē-ˈtā-shən How to pronounce superfetation (audio) \

Definition of superfetation

: a progressive accumulation or accretion reaching an excessive degree

Examples of superfetation in a Sentence

Recent Examples on the Web

But fetuses that appear to have different gestational ages aren't necessarily proof of superfetation., "Yes, You Can Get Pregnant While Already Pregnant. We Asked a Doctor to Explain," 2 Nov. 2017 The rare medical phenomenon is known as superfetation, in which a woman continues to ovulate after becoming pregnant. Char Adams,, "Surrogate Mom Who Gave Birth to Biological Son Says Couple ‘Wanted Me to Buy My Child’," 1 Nov. 2017 The difference in their size was obvious in the first trimester of pregnancy and continued, leading the doctor to offer superfetation as a diagnosis. C. Claiborne Ray, New York Times, "Pregnancy Upon Pregnancy," 27 Feb. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'superfetation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of superfetation

1603, in the meaning defined above

History and Etymology for superfetation

Medieval Latin superfetation-, superfetatio, from Latin superfetare to conceive while already pregnant, from super- + fetare to bear young, from fetus newly delivered — more at fetus

Keep scrolling for more

Learn More about superfetation

Statistics for superfetation

Look-up Popularity

Time Traveler for superfetation

The first known use of superfetation was in 1603

See more words from the same year

Keep scrolling for more

More Definitions for superfetation


variants: or chiefly British superfoetation \ ˌsü-​pər-​fē-​ˈtā-​shən How to pronounce superfoetation (audio) \

Medical Definition of superfetation

: successive fertilization of two or more ova of different ovulations resulting in the presence of embryos of unlike ages in the same uterus

Comments on superfetation

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


a wrong name or inappropriate designation

Get Word of the Day daily email!

Test Your Vocabulary

Summer 2019 Words of the Day Quiz

  • a-bowl-of-peach-sorbet-with-cut-peaches-next-to-it
  • Which is a synonym of desideratum?
True or False

Test your knowledge - and maybe learn something along the way.


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!