fetus

n. young of a human or animal while in the womb or egg

A fetus (or foetus, or fœtus) is a developing mammal or other viviparous vertebrate, after the embryonic stage and before birth. The plural is fetuses (foetuses, fœtuses) or, very rarely, foeti.In humans, the fetal stage of prenatal development begins about eight weeks after fertilization, when the major structures and organ systems have formed, until birth.
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n. fetus, young of a human or animal while in the womb or egg

n. wisp, trace

The postembryonic stage before birth. In humans, the embyronic stage runs from conception to the beginning of the third month of pregnancy and the fetal stage runs from the start of the third month of preganancy until birth.