gul·ly 1 
(g
ŭl
ē)
n. pl. gul·lies 1. A deep ditch or channel cut in the earth by running water after a prolonged downpour.
2. A channel in the side of a mountain, especially one forming a path for avalanches or rockfall.
v. gul·lied, gul·ly·ing, gul·lies
v.tr. To wear a deep ditch or channel in.
v.intr. To form a deep ditch or channel.
[Perhaps alteration of Middle English golet, throat, channel; see GULLET.]