Back fill is a common term used in construction and engineering projects to describe the process of filling a ditch or excavation with soil material. However, there are many other words that can be used to convey the same meaning. Some possible synonyms for back fill include backfilling, refilling, grading, leveling, compacting, packing, tamping, and ramming. Other related words might include embanking, earthmoving, excavating, and landscaping. Whatever term you use, it's important to understand the context and implications of the process, as well as any environmental or safety concerns that may arise during back filling operations.