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.

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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

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Time Traveler for superfetation

Time Traveler

The first known use of superfetation was in 1603

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Cite this Entry

“Superfetation.” Dictionary, Merriam-Webster, Accessed 6 Aug. 2020.

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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

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