acclivity vs mound

acclivity

noun
  • A slope or inclination of the earth, as the side of a hill, considered as ascending, in opposition to declivity, or descending; an upward slope; ascent. 

mound

noun
  • A natural elevation appearing as if thrown up artificially; a regular and isolated hill, hillock, or knoll. 

  • The mons veneris. 

  • Elevated area of dirt upon which the pitcher stands to pitch. 

  • A ball or globe forming part of the regalia of an emperor or other sovereign. It is encircled with bands, enriched with precious stones, and surmounted with a cross. 

  • An artificial hill or elevation of earth; a raised bank; an embankment thrown up for defense 

verb
  • To form a mound. 

  • To force or pile into a mound or mounds. 

  • To fortify with a mound; add a barrier, rampart, etc. to. 

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