harrow vs tear at

harrow

verb
  • To traumatize or disturb; to frighten or torment. 

  • To drag a harrow over; to break up with a harrow. 

  • To break or tear, as if with a harrow; to wound; to lacerate; to torment or distress; to vex. 

noun
  • An obstacle formed by turning an ordinary harrow upside down, the frame being buried. 

  • A device consisting of a heavy framework having several disks or teeth in a row, which is dragged across ploughed land to smooth or break up the soil, to remove weeds or cover seeds; a harrow plow. 

tear at

verb
  • To afflict or aggrieve. 

  • To pull at violently. 

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