Sentence:  Conservatism has come to mean, with us, <WSD>filibusterism</WSD>, the acquisition of our neighbor's land, the extension of negro slavery, the reopening of the slave trade, and placing under the ban of society every publicist who raises his voice against such conservatism. 
Meaning of the word marked with <WSD> tags:  The practice of forcefully and unauthorisedly acquiring control of foreign land.