How to say "great-grandmother" in Japanese

• 曾祖母そうそぼ
  nounCovers the literal kinship sense, a grandparent's mother. A kanji compound, it is the form you meet in writing such as family trees and genealogies rather than in everyday conversation.
• ひいおばあさん
  nounAlso means a grandparent's mother; this is the word you use when actually talking about your great-grandmother, in speech or in writing. It is usually written in kana alone.

Both words mean the mother of one's grandparent, so the choice is about wording: 曾祖母 is the kanji compound you meet in written contexts such as genealogy, while 「ひいおばあさん」 is the everyday term, usually written in kana.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 曾祖母そうそぼgreat-grandmother
• ひいおばあさんgreat-grandmother