DESTROY NOAH'S ARK

[Chas]

fetus
late 14c., from L. fetus "the bearing, bringing forth, or hatching of young," from L. base *fe- "to generate, bear," also "to suck, suckle" (see fecund). In L., this was sometimes transferred figuratively to the newborn creature itself, or used in a sense of "offspring, brood"

The latin defination clearly states that the term describes a baby. A Born viable baby.

Soceity redefined the term to try and take the sting of killing babies out of the process. Even so it does not change the correct understanding of this word.

So you don't know how dictionaries work or how language works.
"late 14c., from L. fetus " That means we adopted that word from the Latin language into English and gave it a meaning. The Latin definition is only of passing interest.

The definition of fetus is a developing mammal or other viviparous vertebrate after the embryonic stage and before birth, not a "born viable baby".

"In humans, the fetal stage commences at the beginning of the ninth week. At the start of the fetal stage, the fetus is typically about 30 millimetres (1.2 in) in length from crown to rump, and weighs about 8 grams. The head makes up nearly half of the fetus' size."

You call that a baby?