Originally Posted by click sidious
Apparently we are looking at conflicting information. I didn't write the definition, I'm just going by what it says.
It's pretty simple.
First you have a zygote, which is simply a fertilized egg.
Then you have some other thing which I forget the name of because I don't have my high school biology textbook handy, which is a zygote which has divided into multiple cells but has not yet implated itself in the uterine wall.
Once whatever that multi-celled cluster thing implants itself in the uterine wall you have an embryo.
After the eighth week of pregnancy, the developing organism is hereafter referred to as a fetus.