English Reference

Word

embryo

Phoneticsem·bryo

US/ˈɛmbɹiˌoʊ/

UK/ˈɛmbɹɪˌəʊ/

Definitions

01early animal development

B2 · Science

n. an animal or human in the very first stage of life, before it becomes a fetus or hatches from an egg.

n. an organism in the early stages of development before birth, hatching, or metamorphosis.

“The scientists studied how the embryo develops inside the egg over two weeks.”

“Research into the genetic markers of the embryo provides critical insights into the early stages of vertebrate development.”

Technical

Usage

In human medicine, the term is strictly used for the first eight weeks after fertilisation.

Synonyms

02part of a seed

C1 · Science

n. the tiny part of a plant seed that can grow into a new plant.

n. the rudimentary plant contained within a seed, consisting of precursor tissues for leaves, stem, and root.

“If the embryo inside the seed is damaged, the plant will not grow.”

“The botanical study focused on how the embryo remains dormant until environmental conditions trigger germination.”

Technical

Synonyms

03early stage of an idea

C1

n. the very beginning of an idea, plan, or project before it is fully formed.

n. the rudimentary or beginning stage of a concept, organisation, or project.

“The global company started as a small embryo of an idea in a garage.”

“The revolutionary policy was still in embryo when the administration changed, leading to its eventual abandonment.”

Literary · Formal

Usage

Often used in the phrase 'in embryo' to mean undeveloped or in the planning stages.

Antonyms

completionfinality

Real-World Examples

“All human embryos initially have identical reproductive tissues that later develop into genitals.”
Phys.org · 19 Aug 2026
“Rachel, who was 39 at the time, needed a sperm donor so her eggs could be fertilised in a lab to create an embryo which could then be implanted into her uterus.”
BBC News · 18 Aug 2026
“In a study published this week in the journal Current Biology , scientists report that the formin gene can control whether snail embryos begin developing a left- or right-curled shell.”
Smithsonian Magazine · 25 Feb 2016

Etymology

Borrowed from Medieval Latin embryō, from Ancient Greek ἔμβρυον (émbruon, “fetus”), from ἐν (en, “in-”) + βρύω (brúō, “to grow, swell”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

embryoNounembryonicAdjective

Related words

Domain

Botany

This entry

Level
C1 · Advanced
Frequency
Frequent
Updated

Scan code

englishreference.com/q/embryo

English Reference