Arlington, town, Middlesex County, northeastern Massachusetts, on the Mystic River; settled in the 1630s as Menotomy, incorporated 1807 as West Cambridge. It is a residential suburb of Boston with some light manufacturing. The town was renamed Arlington (for Arlington, Virginia) in 1867. It was the site of a skirmish (April 19, 1775) that followed the Battle of Concord in the American Revolution. Population 48,219 (1980); 44,630 (1990); 44,630 (1996 estimate).
