isochronous vs recurring

isochronous

adj
  • Happening at the same time; simultaneous. 

  • Happening at regular intervals; isochronal. 

  • of or pertaining to data associated with time-sensitive applications. 

  • Of or pertaining to the use of clocks derived from the same clock reference. 

recurring

adj
  • Happening or occurring frequently, with repetition. 

  • Of a decimal: having a set of digits that is repeated indefinitely. 

noun
  • A recurrence; a coming round again. 

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