Толковый словарь английского языка Oxford English Reference - ia

1. suffix. 1 forming abstract nouns (mania; utopia), often in Med. (anaemia; pneumonia). 2 Bot. forming names of classes and genera (dahlia; fuchsia). 3 forming names of countries (Australia; India). Etymology: from or after L & Gk 2. suffix forming plural nouns or the plural of nouns: 1 from Greek in -ion or Latin in -ium (paraphernalia; regalia; amnia; labia). 2 Zool. the names of groups (Mammalia). IA abbr. US Iowa (in official postal use).