Where does “Aleutian” come from?

Aleutian derives from English Aleut, from Latin -ianus, from Latin -ius, from Latin -um, from Latin -us, from Proto-Indo-European -yós, from Proto-Italic -os, from Proto-Indo-European -ós.

Aleutian (English): Of, from, or pertaining to the Aleutian Islands (a group of islands in the northern Pacific Ocean, west of Alaska), or to its inhabitants, their culture, or their language