fetus

noun

fe·​tus ˈfē-təs How to pronounce fetus (audio)
: 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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Physicians needed to decide what to do if a pregnant woman came to the ER suffering from organ failure, or carrying a fetus with a fatal abnormality. — Literary Hub, 26 Aug. 2026 Children and pregnant women are among the most at risk of severe disease; measles can also harm unborn fetuses. — Adam Kovac, Scientific American, 25 Aug. 2026 But the lawsuit states that Griego suffered an amniotic fluid embolism (AFE) during the delivery, meaning the fluid surrounding the fetus or fetal cells had entered her bloodstream, which can cause sudden heart-lung collapse and massive bleeding. — Alyssa Goldberg, USA Today, 24 Aug. 2026 Medical doctrine had long held that a pregnant patient with an opioid addiction could not be safely detoxed because withdrawal could harm the fetus, causing physical stress and even triggering miscarriage. — Amy Yurkanin, ProPublica, 24 Aug. 2026 See All Example Sentences for fetus

Word History

Etymology

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

First Known Use

14th century, in the meaning defined above

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

Rhymes for fetus

See All Rhymes for fetus

Browse Nearby Words

fettuccine Alfredo
fetus
feu
See all Nearby Words

Cite this Entry

“Fetus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fetus. Accessed 1 Sep. 2026.

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Kids Definition

fetus

noun
fe·​tus ˈfēt-əs How to pronounce fetus (audio)
plural fetuses
: a young animal while in the body of its mother or in the egg especially in the later stages of development
especially : a developing human being in the uterus from usually two months after pregnancy occurs to birth compare embryo sense 1

Medical Definition

fetus

noun
fe·​tus
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)
: 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

More from Merriam-Webster on fetus

Britannica.com: Encyclopedia article about fetus

Last Updated: - Updated example sentences
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