The name of the territory about Casco Bay and Presumpscot River, in the area now included in Cumberland County, Maine.
It was also sometimes applied to those Abnaki Indians by whom it was occupied. Since the section was settled at an early date by the whites, the name soon dropped out of use as applied to the Indians, or rather it was changed to “Casco,” but this was a mere local designation, not a tribal distinction, as the Indians referred to were Abnaki.
The proper form of the word is given by Willis as Uh-kos-is-co, ‘crane’ or ‘heron,’ the first syllable being guttural. These birds still frequent the bay. It is said by Willis to have been the Indian name of Falmouth (Portland), Maine.