a river in the northeastern US, flowing generally north to the Allegheny River at Pittsburgh, Pennsylvania, forming the Ohio River. Length: 206 km (128 miles)
Monongahela in American English
(məˌnɑngəˈhilə; məˌnɑŋgəˈhilə; məˌn ɑngəˈheɪlə)
river in N W.Va. & SW Pa., flowing north to join the Allegheny at Pittsburgh & form the Ohio: 128 mi (206 km)