Acclivities

Part of speech: noun

Definitions

1. A set of upward inclines that contribute to changes in elevation and landscape features
2. Gradual slopes found in geographical areas that denote increases in height and can influence movement
3. Terrain sections that rise gradually forming sloped surfaces pointing upward

Etymology: "Acclivities" is the plural of "acclivity," a noun for a rise of ground, a slope going upward. The singular entered English in 1614, borrowed from the Latin "acclivitas," which came from "acclivis," meaning "ascending." That adjective is built from "ad," meaning "to" or "toward," and "clivus," meaning "slope" or "hill," so the word's core image is simply movement toward a hill. The same Latin root gives English a whole family of words for the opposite of a climb. "Declivity," a downward slope, is built on "de-" ("down") plus the same "clivus," so the pair acclivity and declivity mirror each other, one rising and one falling from a shared slope.