c. 1600, "art of casting metal," from French fonderei, from fondre "to cast," from Latin fundere (past participle fusus) "to melt, cast, pour out," from nasalized form of PIE root *gheu- "to pour." Meaning "establishment for the founding of metallic articles" is from 1640s. Related: Foundryman.
1610s, "part of a city in which Jews are compelled to live," especially in Italy, from Italian ghetto "part of a city to which Jews are restricted," of unknown origin. The various theories trace it to: Yiddish get "deed of separation;" a special use of Venetian getto "foundry" (there was one near the site of that city's ghetto in 1516); a clipped form of Egitto "Egypt," from Latin Aegyptus (presumably in memory of the exile); or Italian borghetto "small section of a town" (diminutive of borgo, which is of Germanic origin; see borough). Extended by 1899 to crowded urban quarters of other minority groups (especially blacks in U.S. cities). As an adjective by 1903 (modern slang usage from 1999). Ghetto-blaster "large, portable stereo cassette-player" is from 1982.