Seymour. 1 Town (1990 pop. 14,288), New Haven co., SW Conn., on the Naugatuck River; settled c.1678, inc. 1850. The town's manufacturing industries decline since the mid-1900s, but cable and wire, electronic components and hardware, car racks, and concrete are produced. 2 City (1990 pop. 15,576), Jackson co., SE Ind.; inc. 1864. A shipping center for a farm area, it is also a manufacturing city.