run out vs taper off

run out

verb
  • To use up; to consume all of something. See also run low, run short. 

  • Used other than figuratively or idiomatically: see run, out. 

  • To extend a piece of material, or clothing. 

  • To get a batsman out via a run out (see runout) 

  • to be got out in this way. 

  • To expire; to come to an end; to be completely used up or consumed. 

  • To conclude in, to end up 

  • To force (someone or something) out of a location or state of being. 

taper off

verb
  • To diminish or lessen gradually; to become smaller, slower, quieter, etc. 

How often have the words run out and taper off occurred in a corpus of books? (source: Google Ngram Viewer )