From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

The official title of the Persian governor of Judaea ( Ezra 2:63;  Nehemiah 7:65;  Nehemiah 7:70); applied to Nehemiah ( Nehemiah 8:9;  Nehemiah 10:1); also to Zerubbabel ( Ezra 2:63). From a Persian root, "his severity." Like the German title of consuls of free and imperial cities, gestrenger herr. So "our most dread sovereign." Ρecheh (our Pasha ) is the title of Nehemiah in  Nehemiah 12:26;  Haggai 1:1;  Haggai 2:2;  Ezra 5:3; implying governor of a province less than a Satrapy .

Hastings' Dictionary of the Bible [2]

Tirshatha . A Persian word = ‘His Excellency,’ or more probably ‘His Reverence,’ mentioned   Ezra 2:63 (=   Nehemiah 7:65 ),   Nehemiah 7:70;   Nehemiah 8:9;   Nehemiah 10:1 . In the first three passages he is unnamed, but is apparently Zerubbabel; in the last two he is Nehemiah. The title is used interchangeably with the Assyr. [Note: Assyrian.] pechah or ‘ governor ,’ of which it may be the Persian equivalent, and apparently represents a plenipotentiary appointed for a special mission.

C. W. Emmet.

Smith's Bible Dictionary [3]

Tirshatha. (always written with the article). The title of the governor of Judea, under the Persians, perhaps derived from a Persian root signifying, Stern, Severe, and it is added as a title, after the name of Nehemiah,  Nehemiah 8:9;  Nehemiah 10:1 and occurs also, in three other places. In the margin of the Authorized Version,  Ezra 2:63;  Nehemiah 7:65;  Nehemiah 10:1, it is rendered as "Governor".

Morrish Bible Dictionary [4]

Persian title given to Nehemiah.  Nehemiah 8:9;  Nehemiah 10:1 . In  Ezra 2:63 , and  Nehemiah 7:65,70 , the same title doubtless refers to Zerubbabel. In the margin it reads 'governor.' It is thought to be similar to the modern word Pasha. This is confirmed by the Hebrew word (pechah), used for the title of Nehemiah in  Nehemiah 12:26 , and elsewhere for the Persian governors.

Holman Bible Dictionary [5]

 Ezra 2:63 Nehemiah 7:65 7:70 Nehemiah 8:9 Nehemiah 10:1

American Tract Society Bible Dictionary [6]

Perhaps meaning severe or august, a title of honor borne by Zerubbabel and Nehemiah as Persian governors of Judea,  Ezra 2:63;  Nehemiah 7:65 .

Easton's Bible Dictionary [7]

 Ezra 2:63 Nehemiah 7:65,70 Nehemiah 8:9 10:1

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [8]

[most Tir'shatha] (Heb. always with the article, hat-Tirshatha', הִתַּרַשָׁתָא ; hence the Sept. gives the word Ἀθερσασθά [4.r. Ἀθερσαθά ].  Ezra 2:63;  Nehemiah 7:65, and Ἀρταρσασθά ,  Nehemiah 10:1; Vulg. Athersatha ) , the title of the governor of Judaea under the Persians, derived by Gesenius from the Persian root Torsh, signifying "stern," "severe." He compares the title Gestrenger Herr, formerly given to the magistrates of the free and imperial cities of Germany (comp. also our expression, "most dread sovereign"). It is added as a title after the name of Nehemiah ( Nehemiah 8:9;  Nehemiah 10:1 [Hebrews 2]); and occurs also. in three other places ( Ezra 2:63, and the repetition of that account in  Nehemiah 7:65-70), where probably it is intended to denote Zerubbabel, who had held the, office before Nehemiah. In the margin of the A. V. ( Ezra 2:63;  Nehemiah 7:65;  Nehemiah 10:1) it is rendered "governor;" an explanation justified by  Nehemiah 12:26, where "Nehemiah the governor הִפֶּחָה ( Pechah, probably from the same root as the word we write pacha, or pasha), occurs instead of the more usual expression" Nehemiah the Tirshatha." This word, פֶּהָה , is twice applied by Nehemiah to himself ( Nehemiah 5:14;  Nehemiah 5:18), and by the prophet Haggai ( Haggai 1:1;  Haggai 2:2;  Haggai 2:21) to Zerubbabel. According to Gesenius, it denotes the prefect or governor of a province of less extent than a satrapy. The word is used of officers and governors under the Assyrian ( 2 Kings 18:24;  Isaiah 36:9), Babylonian ( Jeremiah 51:57;  Ezekiel 23:6;  Ezekiel 23:23; see also  Ezra 5:3;  Ezra 5:14;  Ezra 6:7;  Daniel 3:2-3;  Daniel 3:27;  Daniel 6:7 [Hebrews 8]), Median ( Jeremiah 51:28), and Persian ( Esther 8:9;  Esther 9:3) monarchies. Under this last we find it applied to the rulers of the provinces bordered by the Euphrates ( Ezra 8:36;  Nehemiah 2:7;  Nehemiah 2:9;  Nehemiah 3:7), and to the governors of Judaea, Zerubbabel and Nehemiah (comp.  Malachi 1:8). It is found also at an earlier period in the times of Solomon ( 1 Kings 10:15;  2 Chronicles 9:14) and Benhadad king of Syria ( 1 Kings 20:24), from which last place, compared with others ( 2 Kings 18:24;  Isaiah 36:9),we find that military commands were often held by these governors; the word, indeed, is often rendered by the A. V., either in the text or the margin, "captain." By thus briefly examining the sense of Pechdh, which (though of course a much more general and less distinctive word) is given as an equivalent to Tirshath'. we have no difficulty in forming an opinion as to the general notion implied in it. We have, however, no sufficient information to enable us to explain in detail in what consisted the special peculiarities in honor or functions that distinguished the Tirshatha from others of the same class, governors, captains, princes, rulers of provinces. (See Governor).

International Standard Bible Encyclopedia [9]

tẽr - shā´tha , tûr´sha - tha ( תּרשׁתא , tirshāthā'  ; Ἁθερσαθά , Hathersathá ): A title which occurs 5 times in Ezra and Nehemiah (  Ezra 2:63;  Nehemiah 7:65 , the American Standard Revised Version and the English Revised Version margin "governor"). In  Nehemiah 8:9;  Nehemiah 10:1 , Nehemiah is called the tirshāthā' . In  Ezra 2:63;  Nehemiah 7:65 ,  Nehemiah 7:70 , it is the title of Sheshbazzar, or Zerubbabel. As in  Nehemiah 12:26 , Nehemiah is called a peḥāh , or governor, a title which in  Ezra 5:14 is given to Sheshbazzar also, it has been supposed that peḥāh and tirshāthā' were equivalent terms, the former being of Assyrio-Babylonian and the latter of Persian origin. According to Lagarde, it comes from the Bactrian antarekshatra , that is, "he who takes the place of the king." According to Meyer and Scheftelowitz it is a modified form of a hypothetical Old Persian word tarsata . According to Gesenius and Ewald, it is to be compared with the Persian torsh , "severe," "austere," i.e. "stern lord." It seems more probable that it is derived from the Babylonian root rashu , "to take possession of," from which we get the noun rashu , "creditor." In this case it may well have had the sense of a tax-collector. One of the principal duties of the Persian satrap, or governor, was to assess and collect the taxes (see Rawlinson's Persia , chapter viii). This would readily account for the fact that in  Nehemiah 7:70 the tirshāthā' gave to the treasure to be used in the building of the temple a thousand drachms of gold, etc., and that in  Ezra 1:8 Cyrus numbered the vessels of the house of the Lord unto Sheshbazzar. This derivation would connect it with the Aramaic rashya , "creditor," and the New Hebrew rāshūth , "highest power," "magistrate."