declivity

Three different English words descend from "clivus," the Latin word for "slope" or "hill" - with the help of three Latin prefixes. Declivity combines "clivus" with the prefix de-, meaning "down" or "away." "Acclivity" uses "ad-" (which may change its second letter depending on the root word), meaning "to" or "toward." Hence, an acclivity is an upward slope. The third word has a figurative meaning in English: "proclivity" makes use of the prefix pro-, meaning "forward," and this word refers to a personal inclination, predisposition, or "leaning."