glade vs open space

glade

noun
  • An open passage through a wood; a grassy open or cleared space in a forest. 

  • An everglade. 

  • An open space in the ice on a river or lake. 

  • A bright surface of ice or snow. 

open space

noun
  • An open-air area, such as a park or public garden with no (or very few) buildings, often in an urban area and designated by a local authority or government as such. 

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