XI Meaning of XI in English xi name of Greek letter BrE AmE saɪ ksaɪ, zaɪ, ɡzaɪ AmE zaɪ▷ xis, xi's saɪz ksaɪz, zaɪz, ɡzaɪz AmE zaɪz Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012