-ia

aff. an ending of nouns borrowed from Greek and Latin, or coined in English or other languages on a Latin model, that denote esp. places (Ethiopia; Georgia; Liberia), states or conditions, esp. physical disorders (inertia; insomnia; leukemia; phobia), or plants (fuchsia; zinnia); also occurring in other nouns, often orig. or still plural (bacteria; genitalia; insignia; media) or collective (academia; militia). The ending -ia has limited productivity as an English suffix, forming names of disorders

hypoxia[/ex]

or plural or collective nouns

militaria; psychedelia; suburbia[/ex]

Compare -y II Etymology: < NL, L, Gk