Univerbation of 한〮아비〮 (hánàpí, “grandfather”) + -아〮 (-á, vocative suffix) + -님〯 (-nǐm, honorific suffix). Compare 아비〮 (àpí), 아바〮님〯 (àpánǐm).
한〮아바〮님〯 (hánàpánǐm)