fetus
noun plural[L. faetus.]
fetuses. The young of viviparous animals in the womb, and of oviparous animals in the egg, after it is perfectly formed; before which time it is called embryo. A young animal then is called a fetus from the time its parts are distinctly formed, till its birth. Feu de joie, fire of joy, a French phrase for a bonfire, or a firing of guns in token of joy.