noun
gradient; degree of inclination
Technical term for the steepness of a slope, often used in geography, engineering, and mathematics.
この道路の傾斜度は8パーセントです。
The gradient of this road is 8 percent.
傾斜度が急な坂道では、自転車を押して歩く。
On slopes with a steep gradient, I get off and push my bicycle.
傾斜 means 'inclination' or 'slant' in a broader sense, whereas 傾斜度 specifically refers to the degree or numerical value of that inclination.
Compound of 傾斜 (keisha, 'inclination') + 度 (do, 'degree'). The exact historical derivation is uncertain, but the word follows a common pattern for forming technical terms.