embryo

1 of 2

noun

em·​bryo ˈem-brē-ˌō 

plural embryos

1

a

: an animal in the early stages of growth and differentiation that are characterized by cleavage, the laying down of fundamental tissues, and the formation of primitive organs and organ systems

especially : the developing human individual from the time of implantation to the end of the eighth week after conception

b

archaic : a vertebrate at any stage of development prior to birth or hatching

2

: the young sporophyte of a seed plant usually comprising a rudimentary plant with plumule, radicle, and cotyledons

3

a

: something as yet undeveloped

b

: a beginning or undeveloped state of something

… productions seen in embryo during their out-of-town tryout period …

—Henry Hewes

embryo-

2 of 2

combining form

: embryo

embryogeny

Examples of embryo in a Sentence

Recent Examples on the Web

Noun

More recently research has also highlighted how cannabis use among cancer patients may reduce the effectiveness of immunotherapy treatments, and that its use can impact female egg quality and embryo development. —Jasmine Laws, MSNBC Newsweek, 1 Dec. 2025

For years now, prospective parents who use IVF to have babies have been able to opt for preimplantation genetic testing to make sure the embryo has the correct number of chromosomes. —Amanda Gerut, Fortune, 29 Nov. 2025

But in exchange, Allura would get the embryos. —Tom Smyth, Vulture, 25 Nov. 2025

In July, Kilcullen gave birth to her daughter, Marlowe, thanks to a frozen embryo donated by a couple from Canada. —Sarah Svoboda, CBS News, 21 Nov. 2025

Word History

Etymology

Noun

Middle English embrioun "embryo, fetus," borrowed from Medieval Latin embrion-, embrio, embryo, borrowed from Greek émbryon "newborn creature (in reference to a lamb), young, embryo or fetus," from em- em- + -bryon, derivative of bry-, stem of brýein "to swell with an abundance of growth, bloom, abound," of obscure origin

Note: In Medieval Latin the Greek neuter noun émbryon was reanalyzed as the base of Latin nasal stems (such as sermōn-, sermō "speech"), resulting in the nominative singular form embryo, which was borrowed into English. The stem embryon- was employed in New Latin derivatives, the sources of embryonal and embryonic. Compare bryo-.

Combining form

Late Latin, from Greek, from embryon

First Known Use

Noun

1548, in the meaning defined at sense 1b

Phrases Containing embryo

• embryo sac
• embryo transfer
• in embryo

Rhymes for embryo

• acknow
• aglow
• ago
• airglow
• aloe
• altho
• although
• ammo
• backflow
• backhoe
• banjo
• barbeau

Kids Definition

embryo

noun

em·​bryo ˈem-brē-ˌō 

plural embryos

1

: an animal in the early stages of development that are marked by cleavage, the laying down of the basic tissues, and the formation of primitive organs and organ systems compare fetus

2

: a tiny young plant within a seed

3

: a beginning or undeveloped stage

—used especially in the phrase in embryo

Medical Definition

embryo

noun

em·​bryo ˈem-brē-ˌō 

plural embryos

1

archaic : a vertebrate at any stage of development prior to birth or hatching

2

: an animal in the early stages of growth and differentiation that are characterized by cleavage, the laying down of fundamental tissues, and the formation of primitive organs and organ systems

especially : the developing human individual from the time of implantation to the end of the eighth week after conception compare fetus