Lynn, city (1990 pop. 81,245), Essex co., E Mass.; inc. as a town 1631, as a city 1850. Lynn is an old industrial center. The first ironworks (1643) and the first fire engine (1654) in the country were built there. Formerly the shoe industry was important, but jet engines, marine turbines, and electrical instruments have become the major products. The home of Mary Baker Eddy, the founder of Christian Science, is in Lynn.