fetus

noun

fe·​tus ˈfē-təs 

: 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

But measles infections during pregnancy pose severe, life-threatening risks to both pregnant people and fetuses. — Beth Mole, ArsTechnica, 3 Nov. 2026

The idea is that the donor’s healthy mitochondria power the embryo into a healthy fetus and, eventually, a baby. — Amanda Erickson, STAT, 2 Nov. 2026

Other existing Idaho laws on miscarriage management are limited, mostly focused on the disposal of a fetus’s remains and on vital statistics certificates. — Sarah Cutler, Idaho Statesman, 23 Oct. 2026

After her death, DNA results revealed that Pickard was the father of Birchmore's unborn fetus, not Farwell. — Matt Schooley, CBS News, 21 Oct. 2026

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

Rhymes for fetus

• foetus
• meatus
• thetis
• treatise
• caritas
• mellitus
• cellulitis
• margaritas
• tonsillitis

Kids Definition

fetus

noun

fe·​tus ˈfēt-əs 

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 

plural fetuses or chiefly British foetuses or foeti ˈfēt-ˌī 

: 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