Few words are as ideologically charged as "ghetto." Its early uses centered on two cities: Venice, the site of the first ghetto in Europe, established in 1516; and Rome, where the ghetto endured until 1870, decades after it had been dismantled elsewhere. Over the nineteenth century, as Jews were emancipated and ghettos were dissolved, the word "ghetto" transcended its Italian roots and became a more general term for pre-modern Jewish life. It also came to designate new Jewish spaces—from voluntary immigrant neighborhoods like New York’s Lower East Side to the holding pens of Nazi-occupied Eastern Europe—as dissimilar from the pre-emancipation European ghettos as they were from each other. After World War Two, ghetto broke free of its Jewish origins and became more typically associated with African Americans than with Jews. Chronicling this sinuous transatlantic journey, this talk reveals how the history of ghettos is tied up with the struggle and argument over the meaning of a word.