academic institution vs polytechnic

academic institution

noun
  • An educational institution, dedicated to higher education and research, that grants academic degrees. 

  • An educational institution, dedicated to teaching and/or research. 

polytechnic

noun
  • A three-year post-secondary vocational training institute, equivalent of community college in the U.S. or TAFE in Australia. 

adj
  • that teaches applied arts, sciences, technology, engineering and other academic subjects 

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