Definition that contains allegheny river
- pittsburgh a city in southwestern Pennsylvania where the confluence of the Allegheny River and Monongahela River forms the Ohio River; long an important urban industrial area; site of Carnegie Mellon University and the University of Pittsburgh
- monongahela river a river that rises in northern West Virginia and flows north into Pennsylvania where it joins the Allegheny River at Pittsburgh to form the Ohio River
- monongahela a river that rises in northern West Virginia and flows north into Pennsylvania where it joins the Allegheny River at Pittsburgh to form the Ohio River