- acclivity (n.)
[acclivity 词源字典]
- 1610s, from Latin acclivitatem (nominative acclivitas) "an ascending direction, an upward steepness," from acclivis "mounting upwards, ascending," from ad- "up" (see ad-) + clivus "hill, a slope," from PIE *klei-wo-, suffixed form of *klei- "to lean" (see lean (v.)).[acclivity etymology, acclivity origin, 英语词源]