What is the term for the degree of inclination of a sloped surface?

The term for the degree of inclination of a sloped surface is typically referred to as the "Angle of slope." This term specifically describes the angle formed between the horizontal plane and the slope itself, and it is a crucial concept in engineering and construction for understanding how steep a surface is.

While "Gradient of ramp" might seem appropriate since it also pertains to inclined surfaces, it generally refers to the ratio of vertical rise to horizontal run. This means it is often expressed as a percentage or ratio rather than a specific angle. The terms "Inclination ratio" and "Slant percentage" also refer to measures of steepness but do not specifically capture the concept of an angle as directly as "Angle of slope." Thus, the most accurate and widely recognized term in this context is indeed "Angle of slope."