D

¹

or d

[ dee ]

noun

plural D's or Ds, d's or ds.

1. the fourth letter of the English alphabet, a consonant.
2. any spoken sound represented by the letter D or d, as in dog, ladder, ladle, or pulled.
3. something having the shape of a D .
4. a written or printed representation of the letter D or d.
5. a device, as a printer's type, for reproducing the letter D or d.

d'

²

preposition

1. de (used in French names as an elided form of de ):

   Charles Louis d'Albert.

2. di (used in Italian names as an elided form of di ):

   Gabriele d'Annunzio.

d.

³

abbreviation for

1. (in prescriptions) give.

D

⁴

abbreviation for

1. Electricity. debye ( def ); debyes.
2. deep.
3. depth.
4. Optics. diopter ( def 1 ).
5. divorced.
6. Dutch ( def 7 ).

d'

⁵

1. Informal. contraction of do or did before you:

   How d'you like your eggs cooked? D'you go to the movies last night?

d.

⁶

abbreviation for

1. British. pence.

D

⁷

Symbol.

1. the fourth in order or in a series.
2. (sometimes lowercase) (in some grading systems) a grade or mark, as in school or college, indicating the quality of a student's work as poor or barely passing.
3. (sometimes lowercase) a classification, rating, or the like, indicating poor quality.
4. Music.
   1. the second tone in the scale of C major, or the fourth tone in the relative minor scale, A minor.
   2. a string, key, or pipe tuned to this tone.
   3. a written or printed note representing this tone.
   4. (in the fixed system of solmization) the second tone of the scale of C major, called re.
   5. the tonality having D as the tonic note.
5. (sometimes lowercase) the Roman numeral for 500. Compare Roman numerals.
6. Chemistry. deuterium ( def ). Also 2H
7. Electricity.
   1. electric displacement.
   2. a battery size for 1.5 volt dry cells: diameter, 1.3 inches (3.3 centimeters); length, 2.4 inches (6 centimeters).
8. Biochemistry. aspartic acid.
9. a symbol for a shoe width size narrower than E and wider than C.
10. a proportional brassiere cup size larger than C.

d.

⁸

abbreviation for

1. date.
2. daughter.
3. day.
4. deceased.
5. deep.
6. degree.
7. delete.
8. Physics. density.
9. depth.
10. deputy.
11. dialect.
12. dialectal.
13. diameter.
14. died.
15. dime.
16. dividend.
17. dollar; dollars.
18. dose.
19. drachma.

'd

⁹

1. contraction of had:

   I was glad they'd gone.

2. contraction of did:

   Where'd they go?

3. contraction of should or would:

   He'd like to go. I'd like to remind you of your promise.

4. contraction of -ed:

   She OK'd the plan.

D-

¹⁰

1. Symbol, Biochemistry. (of a molecule) having a configuration resembling the dextrorotatory isomer of glyceraldehyde: always printed as a small capital, roman character.

d-

¹¹

Symbol, Chemistry, Biochemistry.

1. dextrorotatory; dextro- ( l- ).

D.

¹²

abbreviation for

1. day.
2. December.
3. Democrat.
4. Democratic.
5. Physics. density.
6. Deus.
7. Deuteronomy.
8. Doctor.
9. dose.
10. Dutch.

D

¹

abbreviation for

1. Deutsch: indicating the serial number in the catalogue (1951) of the musical compositions of Schubert made by Otto Deutsch (1883–1967)

D.

²

abbreviation for

1. politics Democrat(ic)
2. government Department
3. dinar(s)
4. Don (a Spanish title)
5. Duchess
6. Duke
7. (in the US and Canada) Doctor

d

³

/ diː /

noun

1. the fourth letter and third consonant of the modern English alphabet
2. a speech sound represented by this letter, usually a voiced alveolar stop, as in dagger
3. the semicircle on a billiards table having a radius of 11 1 2 inches and its straight edge in the middle of the baulk line

'd

⁴

contraction of

1. would or had

   you'd

   I'd

d

⁵

symbol for

1. physics density or relative density
2. maths a small increment in a given variable or function: used to indicate a derivative of one variable with respect to another, as in d y /d x
3. chess See algebraic notation

d.

⁶

abbreviation for

1. (in animal pedigrees) dam
2. daughter
3. currency penny or pennies
4. diameter
5. died
6. dinar(s)
7. dollar(s)
8. drachma(s)

D

⁷

symbol for

1. music
   1. a note having a frequency of 293.66 hertz ( D above middle C ) or this value multiplied or divided by any power of 2; the second note of the scale of C major
   2. a key, string, or pipe producing this note
   3. the major or minor key having this note as its tonic
2. chem deuterium
3. maths the first derivative of a function, as in D( x ³ + x ²) = 3 x ² + 2 x
4. physics
   1. dispersion
   2. electric displacement
5. aeronautics drag
6. 1. a semiskilled or unskilled manual worker, or a trainee or apprentice to a skilled worker
   2. ( as modifier ) See also occupation groupings

      D worker

7. Roman numeral 500 See Roman numerals

abbreviation for

1. Germany (international car registration)
2. 1. defence

      I'm playing D in the match this afternoon

   2. defensive play

d

1. Abbreviation of diameter

Word History and Origins

Origin of D¹

From the Latin word dā

Origin of D²

From the Latin word denāriī

Word History and Origins

Origin of D¹

(sense 3 and 6) Latin denarius

Origin of D²

(for sense 8) from German Deutschland