曽そう祖そ父ふ母ぼ

そ

う

そ

ふ

ぼ

Meanings

1

noun

great-grandparents

Refers to the parents of one's grandparents. A straightforward kinship term.

mother

祖そ父ふ母ぼ
祖父母 means grandparents, while 曽祖父母 means great-grandparents (one generation further back).
曾そう祖そ父ふ母ぼ
曾祖父母 is a variant kanji spelling using 曾 instead of 曽; both are read そうそふぼ and have the same meaning.

Compound of 曽 (great-) + 祖父母 (grandparents). The prefix 曽 indicates one generation further back.