fe·​tus | \ ˈfē-təs How to pronounce fetus (audio) \

Definition of fetus

: an unborn or unhatched vertebrate especially after attaining the basic structural plan of its kind specifically : a developing human from usually two months after conception to birth — compare embryo sense 1a

Examples of fetus in a Sentence

Recent Examples on the Web Addressing the 51 million Catholics in the US, the influential body explained that though Pfizer and Moderna used fetus cells for testing, Johnson & Johnson poses the higher moral dilemma because it was developed, tested, and is produced with them. Anne Quito, Quartz, "Vaccine brand “comparison shopping” presents a critical public health challenge," 31 Mar. 2021 Antibodies naturally cross the placenta into the fetus, then persist throughout the first six or so months of the baby’s life, as the infant’s own immune system begins to churn out homemade batches of microbe-vanquishing molecules. Katherine J. Wu, The Atlantic, "New Parents Are Now Vaccinating for Two," 31 Mar. 2021 There’s a tremendous amount of research to show that serious stressors during pregnancy can not only be detrimental for maternal mental health but also impact the fetus, impact maternal child bonding and then, ultimately, a child’s development. Isaac Chotiner, The New Yorker, "Recovering from the Emotional Challenges of the Pandemic," 30 Mar. 2021 House Bill 454 bans a procedure known as dilation and evacuation in which the fetus is removed with instruments, generally after the 14th week of pregnancy. Deborah Yetter, The Courier-Journal, "US Supreme Court to decide whether Daniel Cameron can challenge Kentucky abortion ruling," 29 Mar. 2021 The experiments, at the Weizmann Institute of Science in Israel, were meant to help scientists understand how mammals develop and how gene mutations, nutrients and environmental conditions may affect the fetus. Gina Kolata, Star Tribune, "A 'breakthrough' artificial womb," 25 Mar. 2021 However, experts note that this technology sexes chicks on the 13th day of development, a period where the chick fetus may experience pain. Jonathan Moens, Smithsonian Magazine, "Can New Technologies Eliminate the Grim Practice of Chick Culling?," 17 Mar. 2021 For example, if a woman is exposed to chemicals that block the action of androgens during the first trimester of pregnancy, this can affect the reproductive development of the male fetus in numerous ways. Stacey Colino, Scientific American, "Reproductive Problems in Both Men and Women Are Rising at an Alarming Rate," 16 Mar. 2021 Some chemicals appeared both in pregnant people and their newborn babies, which suggests the chemicals crossed through the placenta into the womb where the fetus developed. Caroline Delbert, Popular Mechanics, "Humans Contain 42 Mystery Chemicals, Which Is Slightly Concerning," 22 Mar. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fetus.' 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 fetus

14th century, in the meaning defined above

History and Etymology for fetus

Middle English, from Latin, act of bearing young, offspring; akin to Latin fetus newly delivered, fruitful — more at feminine

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Time Traveler for fetus

Time Traveler

The first known use of fetus was in the 14th century

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Statistics for fetus

Last Updated

9 Apr 2021

Cite this Entry

“Fetus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fetus. Accessed 17 Apr. 2021.

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More Definitions for fetus



English Language Learners Definition of fetus

: a human being or animal in the later stages of development before it is born


fe·​tus | \ ˈfē-təs How to pronounce fetus (audio) \

Kids Definition of fetus

: an animal not yet born or hatched but more developed than an embryo


variants: or chiefly British foetus \ ˈfēt-​əs How to pronounce fetus (audio) \
plural fetuses or chiefly British foetuses or foeti\ ˈfēt-​ˌī How to pronounce fetus (audio) \

Medical Definition of fetus

: an unborn or unhatched vertebrate especially after attaining the basic structural plan of its kind specifically : a developing human from usually two months after conception to birth — compare embryo

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More from Merriam-Webster on fetus

Nglish: Translation of fetus for Spanish Speakers

Britannica English: Translation of fetus for Arabic Speakers

Britannica.com: Encyclopedia article about fetus

Comments on fetus

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