THASSI.The surname of Simon the Maccabes (1Ma_2:3). The meaning of the word is quite uncertain. As likely an interpretation as any is the zealous.
Hastings' Dictionary of the Bible
Edited by James Hastings, D.D. Published in 1909
thas?ı̄Language:English} (Codex Venetus Θασσεί, Thasseı́; Codex Vaticanus Θασσίς, Thassı́s): The surname of Simon, the brother of Judas Maccabeus (1 Macc 2:3; Syriac ?Tharsi?). It is uncertain what the name means, perhaps ?director? or ?guide,? since Simon was ?a man of counsel,? or ?the zealous.?
International Standard Bible Encyclopedia
PRINTER 1915.
(θασσί, θασσίς; Vulg. Thasi, Hassii), the surname of Simon the son of Mattathias (1 Maccabees 2, 3). The derivation of the word is uncertain. Michaelis suggests תִּדְשַׁי(Chald.), the fresh grass springs up, i.e. the spring is come, in reference to the tranquility first secured during the supremacy of Simon (Grimm, Comment. ad loc.). This seems very farfetched. Winer (Realwb. s.v. Simon ) suggests a connection with תָּסִסfervere, as Grotius (ad loc.) seems to have done before him. In Josephus (Ant. 12:6, 1) the surname is written Ματθῆς, v.r. θαδής, θαθής. SEE MACCABEE.
CYCLOPEDIA OF BIBLICAL, THEOLOGICAL AND ECCLESIASTICAL
press 1895.