[1895–1900; di-1 + phase]This word is first recorded in the period 1895–1900. Other words that entered Englishat around the same time include: apothecaries' measure, calling card, cutback, neon, slapstickdi- is a prefix occurring in loanwords from Greek, where it meant “two,” “twice,” “double”(diphthong). On this model, di- is freely used in the formation of compound words (dicotyledon; dipolar) and in chemical terms (diatomic; disulfide)