The word "ruds" may not be a commonly used word, but there are several synonyms that can be used in its place. Some possible alternatives to "ruds" include "residues," "remnants," "debris," "particles," "sediment," "grains," and "traces." All of these words convey a similar sense of something that remains or is left behind, often after a process of destruction or removal. In some cases, these synonyms may be more appropriate depending on the context of the sentence or the intended meaning. By considering these different options, writers can choose the best word to convey their message clearly and effectively.