Overstrikes, also known as overprints or overmarks, refer to the marks or lines that have been printed on top of or over another printed image or text. These marks are often used to correct an error or to add emphasis to a certain word or phrase. Some synonyms for the word "overstrikes" include cross-outs, deletions, amendments, revisions, additions, modifications, alterations, corrections, and updates. These terms all refer to changes made to an existing document or piece of writing. Using synonyms for overstrikes can add variety to your writing and help avoid repetition.