Meaning of DI- in English
a prefix occurring in loanwords from Greek, where it meant "two," "twice," "double" ( diphthong ); on this model, freely used in the formation of compound words ( dicotyledon; dipolar ) and in chemical terms ( diatomic; disulfide ).
Also, dis- 2 . Cf. mono- .
[ ME dís twice, double, akin to dýo TWO. See BI-, TWI- ]
var. of dis- 1 before b, d, l, m, n, r, s, v, and sometimes g and j: digest; divide.
var. of dia- before a vowel: diorama.
Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012