di

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 ).

a tone in the ascending chromatic scale between do and re.

variant of dis- ¹ before b, d, l, m, n, r, s, v, and sometimes g and j: digest; divide.

variant of dia- before a vowel:

a female given name, form of Diana.

didymium.

Department of the Interior.

drill instructor.

diameter.