arcdegree vs graduation

arcdegree

noun
  • A unit of measurement of angle equal to ¹⁄₃₆₀ of a circle's circumference. 

graduation

noun
  • A marking (e.g., on a container) indicating a measurement on a scale, usually one of many such markings. 

  • A commencement ceremony. 

  • The action or process of graduating (leaving a group). 

  • The exposure of a liquid in large surfaces to the air, so as to hasten its evaporation. 

  • The action or process of graduating and receiving a diploma for completing a course of study (such as from an educational institution). 

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