duplication (n.)

early 15c., "act of doubling," from Old French duplicacion (13c.) and directly from Latin duplicationem (nominative duplicatio), noun of action from past-participle stem of duplicare "to double" (see duplicate (adj.)). Sense of "act of making or repeating something essentially the same" is from 1580s. Meaning "a duplicate copy or version" is by 1872.