From Wiktionary, the free dictionary
From Sanskrit -ईय (-īya).
-ঈয়া • (-ia)
- (in nouns) one from, belonging to, relating to, or like
- (in adjectives) coming from, related to, like
- অসম (oxom, “Assam”) + -ঈয়া (-ia) → অসমীয়া (oxomia, “Assamese”, adjective)