Sister german is an archaic term that refers to a sister who shares both parents with the speaker. There are several synonyms for sister german that are commonly used today, including full sister, blood sister, or biological sister. These terms are more commonly used in modern times to describe a sibling who shares both parents with the speaker. Additionally, the term half-sister is used to describe a sister who shares only one parent with the speaker. Some other terms that may be used to refer to a sister include sibling, sister-in-law, or stepsister. Each term carries a different connotation and is used in different contexts to describe the familial relationship between individuals.