The term 'FAMILY MEM' can be broken down into four crossword solutions: BRO (3 letters), REL (3 letters), SIS (3 letters), and SIB (3 letters). BRO stands for brother, REL stands for relative, SIS stands for sister, and SIB stands for sibling. These terms refer to members of a family, which is typically composed of parents, siblings, and other relatives. Brothers and sisters are the most common family members, while relatives can include aunts, uncles, cousins, and more.