everglade vs glade

everglade

noun
  • A tract of marshland, especially one containing clumps of sawgrass and hammocks of vegetation 

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. 

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