The term "grade" has multiple meanings, depending on its context.
In general usage, a grade refers to a level or standard of quality, performance, or achievement. For example, when talking about schoolwork, grades represent scores given for academic work, with A being the highest and F being the lowest. In this sense, "grade" is often used as a verb meaning to assign a score or mark to something.
In other contexts, such as construction or landscaping, grade refers to the levelness of an area or surface. This usage means that the ground has been leveled out so that it slopes gently from one point to another. In this sense, "grade" is often used as a noun referring to the slope or incline of something.
In summary, the word grade can refer to a level of quality, performance, or achievement in education, or to the levelness of an area or surface in construction and landscaping.