One of the two main possibilities for the meaning of Iscariot is that it refers to the Sicarii, a faction of the Zealots, and hence the name Judas Iscariot would be fairly similar to Judas the Zealot. In turn, Judas the Zealot does not have a clear identity, but is usually thought to be either Saint Jude, or Simon the Canaanite; beginning in 3rd century Syrian tradition, it has been thought by some that Saint Jude is the same individual as Judas Thomas Didymus. Consequently there exists a reasonable possibility that Judas plays a far more significant part in the narrative, but that his identity has been blurred by referring to him in subtly different ways
<snip> (It later discusses the etymology)
What Iscariot signifies is unclear, other than its Greek suffix -otes, like English "-ite" or "-ian". No territory "Iscaria" has ever existed. A birthplace is sometimes offered at the Karioth that is mentioned only once, in a long list of cities in the time of Joshua (Joshua 15:25), concerning which The Classical Gazeteer tactfully remarked "of uncertain position" [4]. Karioth is not mentioned in any text of the centuries before or after Judas Iscariot. (Compare Cana and Arimathea.)
There are two major theories on the meaning of this name, each of which must satisfy certain expectations in order to be credible:
The first of the two main etymologies, which is the one accepted by the majority, and credited to Jerome, derives Iscariot from Hebrew איש־קריות, ÎQrîyôth,1 that is "man of Kerioth", the Judean town (or, more probably, collection of small towns) of Kerioth, not otherwise related to any person or event in the New Testament, nor mentioned in any document of the period, but referred to in the book of Jeremiah. In a similar vein, קריות may be simply the plural of קריה "small city," in which case we have something like "of the suburbs", i.e. it may be the case that Judas Iscariot is nothing more specific than the Jew from the suburbs. As Aramaic was the main language of the time, and all other New Testament characters have Aramaic surnames and nicknames, this Hebrew Judaean name could have marked out Judas as different from the Galilean disciples.
In the second main etymology, "Iscariot" is considered to be a transformation of the Latin sicarius, or "dagger-man". The Sicarii were a cadre of assassins among Jewish rebels intent on driving the Romans out of Judea. It is possible then, that this Latin name might have been transformed by Aramaic into a form more closely resembling "Iscariot". But many historians maintain that the sicarii only arose in the 40's or 50's of the 1st century, so Judas could not have been a member. Brown, Raymond E. (1994). The Death of the Messiah: From Gethsemane to the Grave: A Commentary on the Passion Narratives in the Four Gospels v.1 pp. 688-92. New York: Doubleday/The Anchor Bible Reference Library. ISBN 0-385-49448-3; Meier, John P. (2001). A Marginal Jew: Rethinking the Historical Jesus v. 3 p. 210. New York: Doubleday/The Anchor Bible Reference Library. ISBN 0-385-46993-4 (v.3). While Judas may or may not have actually been a sicariote, the term may have been used for him pejoratively. Therefore, if Judas is largely synonymous with Judean and if Iscariot means Sicarius, then Judas Iscariot would mean Judean Assassin.
In more fringe etymologies theory suggests that "Iscariot" could also be derived from the Aramaic sheqarya' or shiqrai, indicating a person who is a fraud; "the false one" would usually be written as ishqaraya. It could also have been derived from the Hebrew sachar. It also has been theorised that Iscariot could mean deliverer, derived from the Hebrew sakar (Hebraist Joel M. Hoffman's table of Hebrew and Greek names is helpful for understanding this sort of etymology). One factor arguing against "Iscariot" deriving from Judas' betrayal of Jesus is the reference in John 6:71 to Judas as son of Simon the Iscariot. In light of this, Iscariot appears to be a family name, or at least something that could be applied also to his father, which would make these fringe theories unlikely.