Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Centralism \Cen"tral*ism\, n.
The state or condition of being central; the combination of several parts into one whole; centralization.
The system by which power is centralized, as in a government.
Wiktionary
n. A system that centralizes, especially an administration of some kind.
WordNet
n. the political policy of concentrating power in a central organization
Wikipedia
Usage examples of "centralism".
I was sick with the disease of conciliationism towards Menshevism and with a distrustful attitude toward Leninist centralism.
This may, indeed, be changed, but only to substitute for imperial centralism democratic centralism, which were no improvement, or to go back to the system of antagonisms, checks and balances, called constitutionalism, or parliamentary government, of which Great Britain is the model, and which were a return toward barbarism, or mediaeval feudalism.