fetus

n. (brit. Foetus) (pl. -tuses) unborn mammalian offspring, esp. A human embryo of eight weeks or more.  foetal adj. [latin fetus offspring]

n. The young or embryo of an animal in the womb, or in the egg; often restricted to the later stages in the development of viviparous and oviparous animals, embryo being applied to the earlier stages.