See slope in Webster's New World Roget's A-Z Thesaurus II
verb
To depart or cause to depart from true vertical or horizontal:
cant1, heel2, incline, lean1, list2, rake2, slant, tilt, tip2. See straight
noun
Deviation from a particular direction:
cant1, grade, gradient, heel2, inclination, incline, lean1, list2, rake2, slant, tilt, tip2. See rise, straight
Learn more about slope