say it: im-PIR-ee-uh-liz-uhm
imperialism is a noun meaning "a policy of extending your rule over foreign countries". It carries 3 recorded senses.
a policy of extending your rule over foreign countries
a political orientation that advocates imperial interests
any instance of aggressive extension of authority
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for imperialism come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.