Meaning of the Sanskrit Word: prapitamahah

  prapitāmahaḥ—grandfather    Bg 11.39
  prapitāmahaḥ—the great-grandfather Vasiṣṭha    SB 9.1.19
  prapitāmahaḥ—Vasiṣṭha, who was known as the great-grandfather.    SB 9.13.6
  prapitāmahaḥ—(your) great-grandfather    SB 9.24.36

Can't find any compound Sanskrit words containing prapitamahah.