What does allegheny or alleghany mean?
The definition of allegheny and alleghany
Al”le*ghe`ny, a.
1 Of or pertaining to the Allegheny Mountains, or the region where they are situated. Also Al”le*gha`ny.
2 [From the Allegheny River, Pennsylvania.] (Geol.) Pertaining to or designating a subdivision of the Pennsylvanian coal measure.