[1] : The Collaborative International Dictionary of English v.0.48

declivity \decliv"ity\, n.; pl. declivities. l. declivitas,
   fr. declivis sloping, downhill; de + clivus a slope, a hill;
   akin to clinare to incline: cf. f. d'eclivit'e. see
   decline.
   1. deviation from a horizontal line; gradual descent of
      surface; inclination downward; slope; -- opposed to
      acclivity, or ascent; the same slope, considered as
      descending, being a declivity, which, considered as
      ascending, is an acclivity.
      1913 webster

   2. a descending surface; a sloping place.
      1913 webster

            commodious declivities and channels for the passage
            of the waters.                        --derham.
      1913 webster
see also:
declivities decline 

Declivities >> D Words
Declivities, definition of term: Declivities
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