The term "fosses" refers to ditches or trenches that are dug into the ground. These can be used for a variety of purposes, such as drainage, irrigation, or fortification. There are many synonyms for the word "fosses" that describe various types of trenches or ditches, including moats, furrows, gulches, canals, channels, gullies, clefts, ravines, and more. Each of these terms can refer to a slightly different type of ditch or trench, depending on its location, size, shape, purpose, or other characteristics. Choosing the right synonym for "fosses" can help to accurately describe the type of trench or ditch that you are referring to, and enhance the clarity of your writing.