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

Brother Dusk detonates explosives that shatter the cryonic chamber of Cleon clones, bodies raining down in blood and glass, before plucking a single embryo from the wreckage to bait Demerzel’s deepest programming. —Jp Mangalindan, Time, 12 Sep. 2025

As Alien fans know, the facehugger will impregnate its host with a Xenomorph embryo, which eventually bursts from the host's chest. —Christopher Rudolph, PEOPLE, 10 Sep. 2025

Slightly, meanwhile, targets Joe as his patsy to smuggle a Xenomorph embryo out of Prodigy, still resentful that Wendy’s family is here safely while his mother is far away and being threatened by Morrow. —Alan Sepinwall, Rolling Stone, 9 Sep. 2025

EyeEm Mobile GmbH/iStock/Getty Images Plus The study is the first to provide direct evidence that cannabis can impair egg quality and embryo development. —Daniella Gray, MSNBC Newsweek, 9 Sep. 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