zǔ fù
father's father
paternal grandfather
zēng zǔ fù
father's father's father
paternal great-grandfather
wài zǔ fù
maternal grandfather (i.e. mother's father)
zǔ fù bèi
people of one's grandparents' generation
bó shū zǔ fù
father's father's brother
great uncle
zēng wài zǔ fù
great-grandfather (mother's grandfather)