Easton's Bible Dictionary (1897)
Gift, a Persian governor (Heb. pehah, i.e., “satrap;” modern “pasha”) “on this side the river”, i.e., of the whole tract on the west of the Euphrates. This Hebrew title pehah is given to governors of provinces generally. It is given to Nehemiah (5:14) and to Zerubbabel (Hag. 1:1). It is sometimes translated “captain” (1 Kings 20:24; Dan. 3:2, 3), sometimes also “deputy” (Esther 8:9; 9:3). With others, Tatnai opposed the
rebuilding of the temple (Ezra 5:6); but at the command of Darius, he assisted the Jews (6:1-13).
Smith's Bible Dictionary (1863)
(gift), satrap of the province west of the Euphrates in the time of Darius Hystaspes. (Ezra 5:3,6; 6:6,13) (B.C. 520.) The name is thought to be Persian.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
TAT'NAI (gift), a Persian governor in Palestine. Ezr 5:3, 1 Chr 24:6; 1 Kgs 6:6, Lev 6:13.
Hitchcock's Bible Names (1869)
that gives; the overseer of the gifts and tributes