The Collaborative International Dictionary of English v.0.48:
decentralisation \decentralisation\ n. same as decentralization. Syn: decentralization. [WordNet 1.5]WordNet (r) 3.0 (2006):
decentralisation n 1: the spread of power away from the center to local branches or governments [syn: decentralization, decentralisation] [ant: centralisation, centralization]