Finding the right word to describe extended family members can be tricky. While "relative-in-law" is the traditional term for a person who is related to you by marriage, there are several other alternatives that can be used to convey the same meaning. One example is "affine," which refers to a person who is related by marriage rather than by blood. Another option is "kin-in-law," which is a less formal term but still conveys the idea of a family connection through marriage. "In-law relative" is another choice, as is simply referring to the specific relationship, such as "my brother-in-law's sister." Whatever term you choose, be sure to be respectful and clear in your communication.