Umbilical describes things related to the cord that connects a baby to its mother before birth. Inside the womb, a developing baby can't eat or breathe on its own yet, so the umbilical cord delivers oxygen and nutrients from the mother's body directly into the baby's bloodstream. This flexible, rope-like tube keeps the baby alive and growing for nine months. When a baby is born, doctors cut the umbilical cord because the baby can now breathe and eat independently. The small scar left behind becomes your belly button.

The word also describes connections that provide vital support or supplies. Astronauts performing spacewalks stay attached to their spacecraft by an umbilical cord that supplies oxygen and power. A deep-sea diver might rely on an umbilical connection to the surface for air. When engineers say a robot has an umbilical connection, they mean it's tethered by cables that provide power or data.

People sometimes use umbilical metaphorically to describe relationships where someone depends too heavily on another person or place, like a college student who calls home for help with every small decision and struggles to solve problems independently.