Naugatuck (nôgˈətŭkˌ) [key], industrial borough (1990 pop. 30,625), New Haven co., SW Conn., on both sides of the Naugatuck River; settled 1704, inc. 1844. In 1843, Charles Goodyear established the Naugatuck India-Rubber Company there. Rubber is still an important industry in Naugatuck. Other manufactures include candy, chemicals, brass and copper products, and plastics.