river formed in central Nebr. by the North Platte & the South Platte rivers, & flowing eastward into the Missouri: 310 mi (499 km)
Origin:
< Fr Rivière Platte, lit., flat river
See Platte in American Heritage Dictionary 4
A river, about 499 km (310 mi) long, of central Nebraska formed by the confluence of the North Platte and South Platte rivers and flowing eastward to the Missouri River at the Iowa border below Omaha.