freeboard vs mound

freeboard

noun
  • The distance between a water level and the top of something that contains or restrains it (such as a dam). 

  • The distance between the top of sea ice and the water level. 

  • A type of skateboard which simulates the movement of a snowboard when used on a downhill coarse, allowing snowboarding techniques, which has an addition of two centerline casters that extend below the traditional skateboard wheels and bogies. 

  • The vertical distance between the waterline and the uppermost watertight deck of a vessel. 

mound

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

  • The mons veneris. 

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

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

  • 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. 

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 freeboard and mound occurred in a corpus of books? (source: Google Ngram Viewer )