performing or functioning in the best possible manner with the least waste of time and effort; having and using requisite knowledge, skill, and industry; competent; capable: a reliable, efficient assistant.
Marengo is a village in Morrow County, Ohio, United States. The population was 342 at the 2010 census. Marengo is south of Mount Gilead, the county seat.
Marengo, Iowa. Marengo is a town in and the county seat of Iowa County, Iowa, United States. It has served as the county seat since August 1845, even though it was not incorporated until July 1859. The population was 2,528 in the 2010 census, a decline from 2,535 in 2000.