esplanade vs terracing

esplanade

noun
  • Any clear, level space used for public walks or drives; especially, a terrace by the seaside. 

  • A clear space between a citadel and the nearest houses of the town. 

  • The glacis of the counterscarp, or the slope of the parapet of the covered way toward the country. 

  • A grass plat; a lawn. 

terracing

noun
  • A series of terraces. 

  • A stand with a series of tiers. 

  • The formation of terraces. 

  • A terraced structure. 

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