embryo

noun

1. In the reproductive cycle, the stage after the fertilization of the egg that precedes the development into a fetus.
2. An organism in the earlier stages of development before it emerges from the egg, or before metamorphosis.
3. In viviparous animals, the young animal's earliest stages in the mother's body
4. In humans, usually the cell growth up to the end of the seventh week in the mother's body