commutation vs excursion

commutation

noun
  • The process or habit of journeying to and from work on a regular basis; commuting. 

  • The reversal of an electric current. 

  • The change to a lesser penalty or punishment by the State 

  • Substitution, as a means of discriminating between phonemes. 

  • Substitution of one thing for another; interchange. 

  • Specifically, the substitution of one kind of payment for another, especially a switch to monetary payment from obligations of labour. 

excursion

noun
  • A brief recreational trip; a journey out of the usual way. 

  • An occurrence where an aircraft runs off the end or side of a runway or taxiway, usually during takeoff, landing, or taxi. 

  • A deviation in pitch, for example in the syllables of enthusiastic speech. 

  • A wandering from the main subject: a digression. 

verb
  • To go on a recreational trip or excursion. 

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