- declivity (n.)
[declivity 词源字典]
- 1610s, from French déclivité, from Latin declivitatem (nominative declivitas) "a slope, declivity," from declivis "a sloping downward," from de- "down" (see de-) + clivus "a slope," from PIE *klei-wo-, suffixed form of *klei "to lean" (see lean (v.)).[declivity etymology, declivity origin, 英语词源]