The term "down-lying" may not be a commonly used word in everyday vocabulary, but there are several synonyms that can be used in its place. Some options include "flat," "prostrate," "reclining," "recumbent," "horizontally-positioned," and "lying down." Each of these synonyms conveys a similar meaning to down-lying, which refers to something that is lying flat on the ground or surface. Depending on the context in which the word is used, one of these synonyms may be more appropriate than another. By using synonyms, we can expand our vocabulary and communicate our thoughts and ideas more clearly.