[oh-hahy-oh] 
| 1. | a state in the NE central United States: a part of the Midwest. 10,797,419; 41,222 sq. mi. (106,765 sq. km). Capital: Columbus. Abbreviation: OH (for use with zip code), O. |
| 2. | a river formed by the confluence of the Allegheny and Monongahela rivers, flowing SW from Pittsburgh, Pa., to the Mississippi in S Illinois. 981 mi. (1580 km) long. |
| Ohio River A river formed by the confluence of the Allegheny and Monongahela rivers in western Pennsylvania and flowing about 1,578 km (981 mi) to the Mississippi River at Cairo in southern Illinois. Control of the river was contested by the British and French until 1763. The region was ceded to the United States at the end of the Revolutionary War (1783). |
State in the northern United States bordered by Michigan and Lake Erie to the north, Pennsylvania and West Virginia to the east, West Virginia and Kentucky to the south, and Indiana to the west. Its capital is Columbus, and its largest city is Cleveland.
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