duplicate vs repeat

duplicate

verb
  • To do repeatedly; to do again. 

  • To produce something equal to. 

  • To make a copy of. 

noun
  • One that resembles or corresponds to another; an identical copy. 

  • A pawnbroker's ticket, which must be shown when redeeming a pledged item. 

  • The game of duplicate bridge. 

  • The game of duplicate Scrabble. 

  • A biological specimen that was gathered alongside another specimen and represents the same species. 

  • An original instrument repeated; a document which is the same as another in all essential particulars, and differing from a mere copy in having all the validity of an original 

adj
  • In which the hands of cards, tiles, etc. are preserved between rounds to be played again by other players. 

  • Being the same as another; identical, often having been copied from an original. 

repeat

verb
  • To do or say again (and again). 

  • To call in a previous artillery fire mission with the same ammunition and method either on the coordinates or adjusted either because destruction of the target was insufficient or missed. 

  • To refill (a prescription). 

  • To strike the hours, as a watch does. 

  • To commit fraud in an election by voting more than once for the same candidate. 

  • To happen again; recur. 

  • To echo the words of (a person). 

  • To repay or refund (an excess received). 

noun
  • A television program shown after its initial presentation; a rerun. 

  • An iteration; a repetition. 

  • A pattern of nucleic acids that occur in multiple copies throughout a genome (or of amino acids in a protein). 

  • A mark in music notation directing a part to be repeated. 

  • A refill of a prescription. 

How often have the words duplicate and repeat occurred in a corpus of books? (source: Google Ngram Viewer )