breakthrough vs piling up

breakthrough

adj
  • Involving the contraction of a disease by a person with a decreased susceptibility, such as a person who has been vaccinated to help prevent that disease. 

  • Characterized by major progress or overcoming some obstacle. 

  • The emergence or one or more symptoms of a condition despite medication or other medical treatment. 

noun
  • The penetration of the opposition's defence. 

  • An advance through and past enemy lines. 

  • Any major progress; such as a great innovation or discovery that overcomes a significant obstacle. 

  • The penetration of a separating wall or the remaining distance to an adjacent hollow (a crosscut in mining) or between two parts of a tunnel build from both ends; knockthrough. 

piling up

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