When describing past membership, there are several synonyms that can be used instead of "was a member". These include "belonged to", "was part of", "joined", "enlisted in", "affiliated with", and "became a member of". Each of these phrases conveys the same idea of previous membership, but adds variety and specificity to language. Depending on the context and tone, some phrases may be more appropriate than others. Using synonyms can also add interest and complexity to writing, and prevent repetitiveness.