What is another word for "core"?

Roget's Thesaurus (1911) lists these synonyms for "core": affectibility, alive, applicant, aromatic, aspirant, axial, axis, azygous, backbone, bagman, beggar, bidder, bring, bum, buoyancy, cadger, candidate, canvasser, case, center, central, centrality, centralization, centralize, centrally, centrical, chicken, child, claimant, client, column, competitor, concentrate, concentration, concentric, converge, convergence, die, enthusiastic, excitability.