阿婆 is a term of address with several related meanings depending on region and context. In many dialects (especially in southern China) it means 'grandmother' (paternal or maternal). In other contexts it can refer to one's husband's mother (mother-in-law). In modern Mandarin conversation, it's also used as a polite, respectful way to address an elderly woman you don't know — similar to 'ma'am' or 'granny' but warmer. The exact meaning depends on where you are and who you're talking about.