From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Achiacharus , the nephew of Tobit, was governor under Sarchedonus = Esarhaddon ( Tob 1:21 etc.). The nearest Hebrew name is Ahihud (  1 Chronicles 8:7 ).

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

( Ἀχιάχαρος , for Heb. אֲחַיאֲחֲרוֹן brother of the Following, perh. i. q. Posthumous or Latest), the son of Anael (or Ananiel), and the uncle of Tobit ( Tobit 1:21), as also of Nasbas ( Tobit 11:18). He had experienced ingratitude at "the hands of Aman ( Tobit 14:10), but became the cup-bearer and vizier of Sarchedon ( Tobit 1:22), and befriended Tobit ( Tobit 2:10). (See Mordecai).

International Standard Bible Encyclopedia [3]

a - ki - ak´a - rus (Codex Vaticanus Ἀχιάχαρος , Achiácharos  ; Ἀχείχαρος , Acheı́charos ): Governor of Assyria. Achiacharus is the son of Anael, a brother of Tobit (Tobit 1:21). Sarchedonus (Esarhaddon), the king of Assyria, appointed him over all "accounts of his kingdom" and over all "his affairs" (Tobit 1:21f; compare  Daniel 2:48 ). At his request Tobit comes to Nineveh (Tobit 1:22). Achiacharus nourishes Tobit, while the latter is afflicted with disease (Tobit 2:10). He attends the wedding-feast of Tobias (Tobit 11:18). Is persecuted by Aman, but saved (Tobit 14:10).