farthing vs semester

farthing

noun
  • Former British unit of currency worth one-quarter of an old penny; or a coin representing this. 

  • A very small quantity or value; the least possible amount. 

semester

noun
  • Half of a school year (US) or academic year such as autumn or spring semester. 

  • A period or term of six months. 

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