Breitenbach is a proper noun, and it is not possible to provide synonyms for it. However, Breitenbach is a common surname in German-speaking countries, and there are several synonyms that people can use to refer to surnames in general. These synonyms include family name, last name, surname, patronymic, cognomen, and appellation. It is important to note that these terms may have slight differences in their meanings and usage in different contexts. For example, cognomen is often used to refer to a nickname or a descriptive name, while patronymic indicates the father's name.