    Sentence 1: When sdid the. term  imperialism first: come. to be used by  its current definition? . r  Sentence 2: Such writers — have  expanded the time period. associated  with the -terf.~ so. that “it now.  désignates neither a policy, nor a  short space of detades in the late  19th century, but~ a world ‘system  extending over a period of centuries,  often going back ~ to Christopher  Columbus and, in. some accounts, ‘to  the Crusades,