#declivity__descent__fall__decline__downslope  a downward slope
  exclusion:  acclivity
  supertype:  incline__side  an elevated geological formation; "he climbed the steep slope"; "the house was built on the side of the mountain"
  subtype:  downhill.declivity  the downward slope of a hill
  subtype:  steep  a steep place (as on a hill)

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