Easton's Bible Dictionary (1897)
Thanksgiving, referred to by Gamaliel in his speech before the council at Jerusalem (Acts 5:36). He headed an insurrection against the Roman authority. Beyond this nothing is known of him.
Smith's Bible Dictionary (1863)
(God-given), the name of an insurgent mentioned in Gamaliel’s speech before the Jewish council, (Acts 6:35-39) at the time of the arraignment of the apostles. He appeared, according to Luke’s account, at the head of about four hundred men. He was probably one of the insurrectionary chiefs or fanatics by whom the land was overrun in the last year of Herod’s reign. D. 44; but the Theudas mentioned by St. Luke must be a different person from the one spoken of by Josephus.
Hastings' Dictionary of the Bible (1898) & Schaff's Bible Dictionary
THEU'DAS (thanksgiving), an insurrectionary chieftain mentioned by Gamaliel. Acts 5:36, Josephus mentions a similar character of this name, but his insurrection occurred some eleven years after Gamaliel's speech. An explanation of the difficulty is to identify Theudas with Matthias, an eloquent and popular Jewish teacher, who headed a band in the days of Herod and destroyed the Roman eagle set up by the king over the great gate of the temple, being outraged by Herod's impiety. '" But perhaps it is best to say that this Theudas was an obscure individual who is not mentioned elsewhere.
The name was a common one.
Hitchcock's Bible Names (1869)
flowing with water