ADA, a village of Hardin county, 0., U.S.A., on the Pennsyl vania railroad, 15m. E. of Lima, with a population of 2,499 in 193o. It lies on the watershed between the Ohio river and the Great Lakes, in a rich agricultural district. Natural gas is avail able. The village has canning and packing plants, and manufac tures stoves and tiles. It is the seat of the Ohio Northern uni versity (Methodist) which in 1926-27 had an enrolment of about 1,700 students.