scarification vs trench

scarification

noun
  • The act of scarifying: raking the ground harshly to remove weeds, etc. 

  • A medieval form of penance in which the skin was damaged with a knife or hot iron. 

  • A route of administration for some vaccinations and tests: rather than hypodermic injection, the site is inoculated intradermally not with any injection but rather only with small, shallow pricks or scratches; the needle is not hollow. 

  • The scratching, etching, burning / branding, or superficially cutting designs, pictures, or words into the skin as a permanent body modification. 

trench

noun
  • A long, narrow ditch or hole dug in the ground. 

  • A narrow excavation as used in warfare, as a cover for besieging or emplaced forces. 

  • A pit, usually rectangular with smooth walls and floor, excavated during an archaeological investigation. 

  • A trench coat. 

verb
  • To dig or cultivate very deeply, usually by digging parallel contiguous trenches in succession, filling each from the next. 

  • To excavate an elongated pit for protection of soldiers and or equipment, usually perpendicular to the line of sight toward the enemy. 

  • To have direction; to aim or tend. 

  • To cut; to form or shape by cutting; to make by incision, hewing, etc. 

  • To cut furrows or ditches in. 

  • To excavate an elongated and often narrow pit. 

  • To invade, especially with regard to the rights or the exclusive authority of another; to encroach. 

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