叔母さん

1. Origins, structure, and basic meaning

• Structure: 叔母さん, read おばさん, is built from 叔母, a younger female relative in the parents' generation, plus the address suffix さん.
• Basic usage: It denotes a parent's younger sister or the wife of a parent's younger brother, as in 母の妹の叔母さん and 父の弟の妻の叔母さん.

2. Common pitfalls and similar expressions

• Scope and context
  • 叔母 alone does not specify the parental side or whether the relationship is by blood or marriage; さん adds a familiar or polite form of address.