beat a dead horse vs repeat

beat a dead horse

verb
  • To persist or continue far beyond any purpose, interest or reason. 

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 beat a dead horse and repeat occurred in a corpus of books? (source: Google Ngram Viewer )