a rounded, knotty depression in the center of a person’s belly caused by the detachment of the umbilical cord after birth; the umbilicus
complacent self-absorption; concentration on a single issue at the expense of a wider view
a large, seedless orange that has a navellike depression at the top and contains a small secondary fruit underneath it
spend time complacently considering oneself or one’s own interests; concentrate on one issue at the expense of a wider view