di

¹

Or Di

[dee]

preposition

1. from; of: used in Italian personal names, originally to indicate place of origin.

   Conte di Savòia.

di-

²

1. 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 ).

di

³

[dee]

noun

Music.

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

di-

⁴

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

di-

⁵

1. variant of dia- before a vowel.

   diorama.

Di

⁶

[dahy]

noun

1. a female given name, form of Diana.

Di

⁷

Symbol, Chemistry.

1. didymium.

DI

⁸

1. Department of the Interior.

2. drill instructor.

di.

⁹

Or dia

abbreviation

1. diameter.

di-

¹

prefix

1. twice; two; double

   dicotyledon

2. 1. containing two specified atoms or groups of atoms

      dimethyl ether

      carbon dioxide

   2. a nontechnical equivalent of bi- 1

di-

²

combining form

1. variant of dia-

   diopter

DI

³

abbreviation

1. Defence Intelligence

2. Detective Inspector

3. Donor Insemination

Di

⁴

symbol

1. didymium

di–

1. A prefix that means “two,” “twice,” or “double.” It is used commonly in chemistry, as in dioxide, a compound having two oxygen atoms.

Word History and Origins

Origin of di–¹

< Italian < Latin dē

Origin of di–²

Middle English ≪ Latin < Greek, combining form representing dís twice, double, akin to dýo two. See bi- ¹, twi-

Origin of di–³

Perhaps alteration of do ²

Word History and Origins

Origin of di–¹

via Latin from Greek, from dis twice, double, related to duo two. Compare _bi- ¹