I believe "getto" in Venetian originally meant a casting (or the foundry where castings were made). I've never seen the reference specifically to an artillery foundry, though.

The area of Venice where the Ghetto later was located originally had a foundry, but I think it was for coining--that is, a mint. (The famous Zecca, or mint of Venice, is a later building in another part of the city.)

It's worth noting that the original Jewish Ghetto in Venice was a source of great pride to the Jews of Europe. Venice was a very international and tolerant city (there were also resident communities of Turks, Armenians, Greeks, Germans--including Lutherans, after the Reformation--in fact, Venice was excommunicated more than once by the pope, in part because of its lax attitude toward heretics.) There were Jews in Venice from a very early date--I think much earlier than 1385 (the first Jewish cemetary was permitted in an outer island of the city in 1394).

The Venetian Jews were transferred to the area called the Ghetto from other scattered quarters of the city around 1500, because the city government sought to protect them from persecution (mainly by militant Franciscan monks) by consolidating their community and guarding it (with protective walls and a guarded gate). So the original purpose of the walls was not to enclose or isolate them, but to keep marauders out. The Jews of Venice could, I believe, own the land where their homes were, within the Ghetto precinct. Harsh though this may seem to us, it was very progressive at the time. In fact, Jews suffering persecution in other European cities sought to have ghettos constructed on the Venetian model. Only later did the district become rundown, and that was in part because of a booming population that could not expand because of the walls. So they built tall apartment buildings, and the district grew cramped and somewhat wretched.

As to the "h": Italian and Venetian pronounce getto with a soft g, and ghetto as in English, with a hard g. German Jews who came to Venice and settled in the Ghetto (where there is still a handsome 16th c. German, Ashkenazic-rite synagogue) tended to pronounce "getto" with a hard g.

Venetian dialect also tends to drop double consonants from Italian, so the name is sometimes spelled Gheto or Geto in old documents.


Other words given to English by the Venetian dialect:

sequin (from zecchino, a small Venetian coin (from zecca, mint)
arsenal (from darsena, which is a Venetian borrowing from Arabic; I think the word means wharf or harbor)--and BTW, this is a toponymic word too, since the original Arsenal is the medieval shipyard of Venice; the name only later became a word for military storehouse
gazette (I forget the source of this word in Venetian)