Passaic (pəsā´Ĭk), city (1990 pop. 58,041), Passaic co., NE N.J., a port on the Passaic River; settled 1678 by Dutch traders as Acquackanonk, named Passaic 1854, inc. as a city 1873. Formerly a great textile center, it now produces rubber goods, factory equipment, chemicals, plastics, aluminum foil, and other goods. The city has been the scene of considerable labor unrest; an Industrial Workers of the World strike occurred in 1912, and an important strike in protest against a wage cut and involving the right of assembly occurred in 1926.

Passaic, river, c.80 mi (130 km) long, rising near Morristown, NE N.J., and flowing with a winding course NE then S past several industrial towns to Newark Bay. It is navigable by large vessels to the rapids above Passaic. At Paterson is the Great Falls of the Passaic (70 ft/21.3 m high), a national natural landmark. The river's power aided the growth of industry in NE New Jersey that began in the late 18th cent.