embryo

noun, plural em·bry·os.

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.Compare fetus.
2. Botany. 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.

adjective

5. embryonic.

1. a combining form representing embryo in compound words: embryology.

noun plural -bryos

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 pregnancyCompare 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 developmentan embryo of an idea

n.

mid-14c., from Medieval Latin embryo, from Greek embryon “a young one,” in Homer, “young animal,” later, “fruit of the womb,” literally “that which grows,” from en “in” (see en- (2)) + bryein “to swell, be full.”

n. pl. em•bry•os

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

pref.

1. Embryo:embryogenesis.

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.

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.