[ em-bree-oh ]
/ ˈɛm briˌoʊ /

noun, plural em·bry·os.

the young of a viviparous animal, especially of a mammal, in the early stages of development within the womb, in humans up to the end of the second month.Compare fetus.
Botany. the rudimentary plant usually contained in the seed.
any multicellular animal in a developmental stage preceding birth or hatching.
the beginning or rudimentary stage of anything: He charged that the party policy was socialism in embryo.


Origin of embryo

1580–90; < Medieval Latin embryon-, embryo < Greek émbryon, noun use of neuter of émbryos ingrowing, equivalent to em- em-2 + bry- (stem of brýein to swell) + -os adj. suffix

Definition for embryo (2 of 2)


a combining form representing embryo in compound words: embryology.
Also especially before a vowel, embry-.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for embryo

British Dictionary definitions for embryo


/ (ˈɛmbrɪˌəʊ) /

noun plural -bryos

an animal in the early stages of development following cleavage of the zygote and ending at birth or hatching
the human product of conception up to approximately the end of the second month of pregnancyCompare fetus
a plant in the early stages of development: in higher plants, the plumule, cotyledons, and radicle within the seed
an undeveloped or rudimentary state (esp in the phrase in embryo)
something in an early stage of developmentan embryo of an idea

Derived Forms

embryoid, adjective

Word Origin for embryo

C16: from Late Latin, from Greek embruon, from bruein to swell
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for embryo (1 of 2)


[ ĕmbrē-ō′ ]

n. pl. em•bry•os

An organism in its early stages of development, especially before it has reached a distinctively recognizable form.
An organism at any time before full development, birth, or hatching.
The fertilized egg of a vertebrate animal following cleavage.
In humans, the prefetal product of conception from implantation through the eighth week of development.

Medicine definitions for embryo (2 of 2)



The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Science definitions for embryo


[ ĕmbrē-ō′ ]

An animal in its earliest stage of development, before all the major body structures are represented. In humans, the embryonic stage lasts through the first eight weeks of pregnancy. In humans, other placental mammals, and other viviparous animals, young born as embryos cannot thrive. In marsupials, the young are born during the embryonic stage and complete their development outside the uterus, attached to a teat within the mother's pouch.
The developing young of an egg-laying animal before hatching.
The sporophyte of a plant in its earliest stages of development, such as the miniature, partially developed plant contained within a seed before germination.

Related forms

embryonic adjective (ĕm′brē-ŏnĭk)
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Culture definitions for embryo


[ (em-bree-oh) ]

A developing plant or animal. A plant embryo is an undeveloped plant inside a seed. An animal embryo is the animal as it develops from the single cell of the zygote until birth. Among humans and most other mammals, the embryo is carried in the mother's womb.


The term is occasionally used to denote a new or developing idea or project: “The idea for the complete theory was already present in his work, in embryo form, in 1950.”
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.