fourth vs trimester

fourth

noun
  • A quarter, one of four equal parts of a whole. 

  • The fourth gear of an engine. 

  • A musical interval which spans four degrees of the diatonic scale, for example C to F (C D E F). 

  • The person or thing in the fourth position. 

verb
  • To agree with a proposition or statement after it has already been thirded. 

adj
  • The ordinal form of the number four. 

trimester

noun
  • A period of three months or about three months; (financial): quarter. 

  • One of the terms of an academic year in those learning institutions that divide their teaching in three roughly equal terms, each about three months long. Compare semester. 

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