MASTERY Meaning of MASTERY in English mastery BrE AmE ˈmɑːst ə r |i ⇨ˈmɑːs tr|i; § ˈmæst ə r |i, ⇨ § ˈmæs tr|i AmE \ ˈmæst ə r |i ⇨ˈmæs tr|i ▷ mastery|ies iz Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012