d

1 of 6

noun

ˈdē 

plural d's or ds ˈdēz 

often capitalized, often attributive

1

a

: the 4th letter of the English alphabet

Her middle initial is d.

b

: a graphic representation of this letter

a half moon in the shape of a d

c

linguistics : the speech sound that the written letter d represents : a speech counterpart of orthographic d

2

Roman numerals : five hundred see Table of Numbers

3

music : the second tone of a C-major scale (see scale entry 5 sense 1)

in the key of d

4

: a graphic device for reproducing the letter d

the d on my computer keyboard

5

: one designated d especially as the fourth in order or class

option d

6

education

a

: a grade rating a student's work as poor in quality

got a d on the test

b

: one graded or rated with a D

7

: something shaped like the letter D

specifically : a semicircle on a pool table about 23 inches in diameter for use especially in snooker

8

capitalized, sports

a

: defense sense 2b

play tough D

b

: defense sense 4b

d

2 of 6

abbreviation (1)

1

date

2

daughter

3

day

4

dead; deceased

5

deci-

6

degree

7

[Latin denarius, denarii] penny; pence

8

depart; departure

9

diameter

10

differential

11

dimensional

12

distance

13

dorsal

14

down (see down entry 5 sense 6)

15

drive; driving

D

3 of 6

abbreviation (2)

1

Democrat

2

derivative

3

dollar

4

Dutch

D

4 of 6

symbol (1)

deuterium

d-

5 of 6

prefix

ˌdē,

ˈdē

1

: dextrorotatory

d-tartaric acid

2

: having a similar configuration at a selected carbon atom to the configuration of dextrorotatory glyceraldehyde

—usually printed as a small capital

d-fructose

-d

6 of 6

symbol (2)

—used after the figure 2 or 3 to indicate the ordinal number second or third

2d

53d

Examples of d in a Sentence

Noun

Many people who are learning to read confuse b's and d's.

names that start with d

The song is in the key of D.

She got a D on her chemistry test.

Word History

Etymology

Prefix

International Scientific Vocabulary, from dextr-

First Known Use

Noun

before the 12th century, in the meaning defined at sense 1a

Phrases Containing d

• d-bag

Kids Definition

d

noun

ˈdē

plural d's or ds

often capitalized

1

: the fourth letter of the English alphabet

2

: five hundred in Roman numerals see number

3

: the musical note referred to by the letter D : the second tone of the C-major scale

4

: a grade rating a student's work as poor

Medical Definition

d

1 of 3 abbreviation

1

dalton

2

date

3

daughter

4

day

5

dead

6

deceased

7

deciduous

8

degree

9

density

10

developed

11

deviation

12

dexter

13

diameter

14

died

15

diopter

16

disease

17

divorced

18

dorsal

19

dose

20

duration

D

2 of 3 symbol

deuterium

d-

3 of 3 prefix

ˌdē, ˈdē

1

: dextrorotatory

—usually printed in italic

d-tartaric acid

2

: having a similar configuration at a selected carbon atom to the configuration of dextrorotatory glyceraldehyde

—usually printed as a small capital

D-fructose

Legal Definition

D

abbreviation

1

district

2

defendant