Come learn 2000+ kanji and 6000+ vocabulary words with WaniKani.
The Empire (帝国) ism (主義) is when you are doing imperialism. Long live the emperor!
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own. Will help to know the two words this word is made up of, 帝国 and 主義.
Is your country an imperialistic nation?