North Andover (ănˈdōvər) [key], town (1990 pop. 22,792), Essex co., NE Mass., on the Merrimack River, in a dairy and farm area; settled c.1644, set off from Andover and inc. 1855. A former textile town, its manufactures include telephone equipment, chemicals, paper products, valves, prepared foods, and plastics. It is the seat of Merrimack College, the Brooks School (college preparatory), and a Boston Univ. theology center. The scenic spring-fed Lake Cochichewick is nearby.