There are a few different terms that can be used as synonyms for the phrase "lithographic pencil." One possible option is "litho pencil," which is a shortened version of the original term. Another potential synonym is "grease pencil," as these writing tools are often used on greasy or non-porous surfaces. Additionally, the term "china marker" can be used to refer to a type of lithographic pencil that is made with a wax-like substance and can be used on a variety of surfaces. Other terms that may be used as synonyms could include "drawing pencil," "sketching pencil," or "art pencil," depending on the specific context.