cull vs single out

cull

verb
  • To pick or take someone or something (from a larger group). 

  • To select animals from a group and then kill them in order to reduce the numbers of the group in a controlled manner. 

  • To kill (animals etc). 

  • To lay off in order to reduce the size of, get rid of. 

  • To gather, collect. 

noun
  • A lobster having only one claw. 

  • A selection. 

  • An individual animal selected to be killed, or item of produce to be discarded. 

  • A piece unfit for inclusion within a larger group; an inferior specimen. 

  • An organised killing of selected animals. 

  • A fool, gullible person; a dupe. 

single out

verb
  • To select one from a group and treat differently. 

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