slope

(noun) an elevated geological formation. Synonyms: incline, side. Examples: "He climbed the steep slope." "The house was built on the side of a mountain."

(noun) the property possessed by a line or surface that departs from the horizontal. Synonyms: gradient. Example: "A five-degree gradient."

(verb) be at an angle. Synonyms: incline, pitch. Example: "The terrain sloped down."