DI- Meaning of DI- in English di- /daɪ, dɪ/ BrE AmE prefix [ Language: Greek ; Origin: 'two' ] two, twice, or double:A diphthong is a vowel made up of two sounds. ⇨ ↑ semi- , ↑ bi- , ↑ tri- Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012