Womb.
the womb
Womb
Womb.
womb
Uterus.
True.
Womb is another term for uterus.
Fraternal twins each have their own umbilical cord, just like they have their own sac. The two of them are just the same as two siblings with the same birth date.
The name is originally from Greek δελφίς (delphís), "dolphin", which was related to the Greek δελφύς (delphus), "womb". The animal's name can therefore be interpreted as meaning "a 'fish' with a womb".
uterus
womb.