Fetus or foetus?
fetus is a noun meaning “An unborn or unhatched vertebrate showing signs of the mature animal”; foetus is a noun meaning “Alternative spelling of fetus”. Wiktionary gives them as spellings of the same word. In written English (wordfreq, 2021 data) fetus is about 6.6 times as common as foetus.
What is the difference between fetus and foetus?
| fetus | foetus | |
|---|---|---|
| Part of speech | noun | noun |
| Meaning | AustraliaCanadaUSAn unborn or unhatched vertebrate showing signs of the mature animal AustraliaCanadaUSA human embryo after the eighth week of gestation | CommonwealthAlternative spelling of fetus |
| Example | Several feti were removed from every rats' uterus, stripped of their membranes and allowed to lie in the peritoneal cavity connected to the… | none recorded |
| Forms | fetuses, feti, fetii | foetuses, foeti |
| Pronunciation | /ˈfiːtəs/ | not recorded |
| In writing | 4.0 times per million words | about once in every 2 million words |
Sources: fetus and foetus in the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Every current meaning of fetus and foetus
fetus
- 1
AustraliaCanadaUSAn unborn or unhatched vertebrate showing signs of the mature animal
Several feti were removed from every rats' uterus, stripped of their membranes and allowed to lie in the peritoneal cavity connected to the placenta by the umbilical cord and with…
- 2
AustraliaCanadaUSA human embryo after the eighth week of gestation
The sequence is: molecules in reproductive systems, then gametes, zygotes, morulas, blastocysts, and then fetuses
foetus
- 1
CommonwealthAlternative spelling of fetus
Source: the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); obsolete, archaic, dialect and rare senses left out.
Which is more common, fetus or foetus?
fetus appears 4.0 times per million words; foetus about once in every 2 million words.
fetus 4.0 times per million wordsfoetus about once in every 2 million words
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How many people search fetus vs foetus?
“fetus vs foetus” is searched about 70 times a month on Google and 10 on Bing in the United States. Google counts close variants of a query together (“foetus vs fetus”, “fetus or foetus”).
Sources: Google Ads keyword data through DataForSEO and Microsoft Advertising keyword data through DataForSEO, the average month from September 2025 to August 2026.