THESAURUS
Umbilicus
axis, center, center of action, center of gravity, centroid, centrum, core, dead center, epicenter, heart, hub, kernel, marrow, medulla, metacenter, middle, nave, navel, nub, nucleus, omphalos, pith, pivot, storm center
ROGET THESAURUS
Umbilicus
Centrality
N
centrality, centricalness, center, middle, focus, core, kernel, nucleus, nucleolus, heart, pole axis, bull's eye, nave, navel, umbilicus, backbone, marrow, pith, vertebra, vertebral column, hotbed, concentration, centralization, symmetry, center of gravity, center of pressure, center of percussion, center of oscillation, center of buoyancy, metacenter, central, centrical, middle, azygous, axial, focal, umbilical, concentric, middlemost, rachidian, spinal, vertebral, middle, midst, centrally.