Diesel oil, also known as diesel fuel, is a type of petroleum distillate commonly used in diesel engines. However, there are many other terms that are used to describe this fuel in different geographic regions or industries. Some common synonyms for diesel oil include "petrodiesel," "fuel oil," "diesel fuel oil," and "gas oil." In agriculture, it is known as "farm diesel," while in marine transportation, it is referred to as "marine diesel." In addition, some companies use their own specific brand names for their fuel products. Regardless of the terminology used, diesel oil is widely used as a reliable and efficient fuel source for a range of applications.