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• embryo
  embryo

  noun

  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.
• embryo-
  embryo-

  a combining form representing embryo in compound words.

embryo

¹ American  

[em-bree-oh] / ˈɛm briˌoʊ /

noun

plural

embryos

1. 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.

2. the rudimentary plant usually contained in the seed.

3. any multicellular animal in a developmental stage preceding birth or hatching.

4. the beginning or rudimentary stage of anything.

   He charged that the party policy was socialism in embryo.

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adjective

1. embryonic.

embryo- ² American  

1. a combining form representing embryo in compound words.

   embryology.

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embryo British  

/ ˈɛmbrɪˌəʊ /

noun

1. an animal in the early stages of development following cleavage of the zygote and ending at birth or hatching

2. the human product of conception up to approximately the end of the second month of pregnancy Compare fetus

3. a plant in the early stages of development: in higher plants, the plumule, cotyledons, and radicle within the seed

4. an undeveloped or rudimentary state (esp in the phrase in embryo )

5. something in an early stage of development

   an embryo of an idea

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embryo Scientific  

/ ĕm′brē-ō′ /

1. 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.

2. The developing young of an egg-laying animal before hatching.

3. The sporophyte of a plant in its earliest stages of development, such as the miniature, partially developed plant contained within a seed before germination.

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embryo Cultural  

1. 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.

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Usage

What does embryo- mean? Embryo- is a combining form used like a prefix representing the word embryo. It is often used in scientific terms, especially in anatomy and biology. Embryo- ultimately comes from the Greek émbryos, meaning “ingrowing.”What are variants of embryo-?When combined with words or word elements that begin with a vowel, embryo- becomes embry-, as in embryectomy.

Discover More

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.”

Other Word Forms

• embryoid
  adjective

Etymology

Origin of embryo

First recorded in 1580–90; from Medieval Latin embryo, embryon-, from Greek émbryon, noun use of neuter of émbryos “ingrowing,” equivalent to em- “in” + bry- (stem of brýein “to swell”) + -os adjective suffix; em- ²

Explanation

An embryo is an animal in the phase after fertilization but before birth or hatching. Embryos still live in the womb or egg. Do you remember when you were an embryo? Probably not, because you were just a tiny clump of cells in your mother's womb — you weren't born yet. All animals were embryos at one point: it's a very early stage of life. Another meaning is not as literal: the beginning of an idea could be called an embryo, as in, "My plan for ice-skating robots is still in the embryo stage." That means the idea isn't very developed.

Example Sentences

The 22-year-old from eastern Ukraine is a surrogate, pregnant with an embryo from a Chinese couple's egg and sperm.

From BBC • May 7, 2026

An in-person doctor’s visit is the only reliable way to diagnose an ectopic pregnancy—a life-threatening condition in which an embryo implants outside the uterus.

From The Wall Street Journal • May 4, 2026

In Chloe’s case, she began the pregnancy process by contracting with a fertility clinic to implant an embryo conceived with Silvia’s egg and Fausto’s sperm.

From Los Angeles Times • Apr. 25, 2026

In the UK, in 2023, more than 50,000 patients had IVF cycles - where eggs are fertilised in a lab and the embryo is then placed in the woman's uterus.

From BBC • Apr. 3, 2026

Bean shaped and smaller than a speck of sand, the fruit fly embryo begins its life in a whir of activity.

From "The Gene" by Siddhartha Mukherjee