Besmutch is a word that is infrequently used, and it means to soil or tarnish something. There are a variety of synonyms that can be used to describe this act, including smudge, stain, blemish, mar, defile, taint, pollute, infect, corrupt, and sully. When an object is besmutched, it can often take a lot of effort to restore it to its original state. Synonyms for besmutch can be used in various contexts, such as to describe the appearance of a piece of clothing, the reputation of a person or organization, or the cleanliness of a space. Overall, besmutch is just one of many words that can be used to describe something that has been soiled or stained in some fashion.