Allegheny

American  

[al-i-gey-nee] / ˌæl ɪˈgeɪ ni /

noun

1. a river flowing NW from Pennsylvania into SW New York and then S through W Pennsylvania, joining the Monongahela at Pittsburgh to form the Ohio River. 325 miles (525 km) long.

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Other Word Forms

• Alleghanian adjective
• Alleghenian adjective
• trans-Alleghenian adjective

Example Sentences

In Pennsylvania, Democrat Jen Mazzocco won her race in Allegheny County by 64 points — doubling the margin her predecessor had posted in 2024.

From Salon • Feb. 25, 2026

Allegheny County Executive Sara Innamorato called the closure a loss “when it comes to transparency in government, accountability from our institutions, and learning about what is happening in our communities.”

From The Wall Street Journal • Jan. 7, 2026

The county executive explained the options: default, or refinance the bonds at a cost of $400 million to Allegheny County.

From Slate • Nov. 24, 2025

He eventually was carted off and taken to Allegheny General Hospital in critical condition.

From Los Angeles Times • Sep. 11, 2025

Throughout the years, Pittsburgh had welcomed all—anyone who wanted to work hard could come to the confluence of the Allegheny and Monongahela Rivers.

From "Ophie's Ghosts" by Justina Ireland