What word does your mother always say?
umbilical cord n.
The flexible cordlike structure connecting a fetus at the navel with the placenta and containing two umbilical arteries and one vein that transport nourishment to the fetus and remove its wastes. Also called funis.
A ropelike structure that connects a developing embryo or fetus to the placenta. The umbilical cord contains the blood vessels that supply the embryo or fetus with nutrients and remove waste products. Connected to the abdomen of the embryo or fetus, the umbilical cord is cut at birth, leaving a small depression — the navel, or “belly button.”
Note: The detaching of the umbilical cord provides a figure of speech for new independence: “He finally cut the umbilical cord and moved out of his parents' home.”