-ARIUM Meaning of -ARIUM in English -arium combining form BrE AmE ˈeər i‿əm AmE ˈer- ˈær- ▷ — planetarium ˌplæn ə ˈteər i‿əm ˌ•ɪ- AmE -ˈter- -ˈtær- Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012