[n] a copy that corresponds to an original exactly; "he made a duplicate for the files"
[n] something additional of the same kind; "he always carried extras in case of an emergency"
[adj] being two identical
[adj] identically copied from an original; "a duplicate key"
[v] increase twofold; "The population doubled within 50 years"
[v] make or do or perform again; "He could never replicate his brilliant performance of the magic trick"
[v] make a duplicate or duplicates of; "Could you please duplicate this letter for me?"
[v] duplicate or match; "The polished surface twinned his face and chest in reverse"
double, double, duplication, extra, matched, matching, parallel, reduplicate, repeat, replicate, same, twin, twin(a), twinned