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

Vaccination during pregnancy can offer protection from birth due to antibodies that pass from the mother to the developing fetus. —Annette Regan, The Conversation, 29 Apr. 2025

As the Tdap takes full effect, protective antibodies are transmitted to the fetus. —Caroline C. Boyle, USA Today, 20 Apr. 2025

To cut Stinnett’s fetus from her womb and return to Kansas to claim the child as her own. —Nicole Acosta, People.com, 19 Apr. 2025

Chandler-Scott was arrested after a witness reported seeing her place a fetus in a bag and put the bag in a dumpster outside, according to the local media outlet 11 Alive. —Lee Habeeb, MSNBC Newsweek, 4 Apr. 2025

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
• civitas
• 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