MAGNESIA Meaning of MAGNESIA in English magnesia, M\~ BrE AmE mæɡ ˈniːʃ ə məɡ-, -ˈniːs i‿ə, -ˈniːʒ ə, -ˈniːz i‿ə Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012