D, d [Called ‘dee’]. The 4th LETTER of the Roman ALPHABET as used for English. It originated in the triangular Phoenician symbol called daleth (akin to Hebrew dālāh, ‘door’), which was altered by the Greeks to form their delta (Δ), and later rounded to form Roman D.

Sound values

In English, d normally represents the voiced alveolar plosive. However: (1) The boundary between d and its close phonetic neighbours t and th is sometimes breached. Formerly, for example, there was variation between d and th: father and mother were until the 16c written fader and moder; burden and murder were until the 19c written burthen and murther. After voiceless consonants (with the exception of /t/), the past-tense inflection d is pronounced /t/: sacked, touched, stuffed, sipped, hissed, wished, earthed, waxed. (2) In AmE and AusE, intervocalic /t/ is typically voiced to /d/, making homophones of such pairs as Adam/atom, ladder/later, and waded/waited. (3) When the sound usually represented by y follows a d, the two sounds may merge to produce a j-sound /dʒ/: grandeur, procedure. This is acknowledged in the colloquial spellings of Acadian, Barbadian, Indian, soldier as Cajun, Bajan, Injun, sojer.

Double D

Two ds occur: (1) In monosyllables beginning with a vowel: add, odd. (2) In many disyllables after a stressed short vowel: madden, meddle, midden, shoddy, muddy (but contrast shadow, medal, widow, modest, body, study). (3) In monosyllables containing a short vowel when followed by suffixes: bed, bedder, bedded, bedding. (4) When the Latinate prefix ad- precedes a root beginning with d: addition, address, adduce.

Variations on -ED

The regular past-tense inflection adds -ed to the verb stem (sail/sailed, stucco/stuccoed), or -d if the stem already ends in e (love/loved, hate/hated, free/freed, sue/sued, face/faced, rage/raged). However, there is significant systematic variation in both spelling and pronunciation. There are also irregular past-tense forms, some using irregular t alongside regular forms with d (costed/cost, smelled/smelt), some with t and without an ed equivalent (caught, felt, left, lost, put, spent), some using only the d of the base form (fed, found, shed, slid, stood, etc.). and some introducing d in an irregular way (fled, had, heard, made, paid, said, shod, sold, etc.).

After a single vowel letter pronounced short in a stressed syllable, a final consonant is normally doubled when -ed is added: bat/batted, fit/fitted, commit/committed, refer/referred (contrast headed, hatched, with multiple vowel or consonant letters). Final -ic becomes -ick- when -ed is added: picknicked, trafficked. Final consonant plus y changes y to i: carry/carried, deny/denied, pity/pitied (contrast convey/conveyed). This rule results in the single homographic past form skied from to ski and to sky. Words of more than one syllable, not stressed on the final syllable, do not normally double the final consonant (offer/offered), but there are exceptions. In BrE, for example, there is a subrule that unstressed final -el becomes -elled (travel/travelled), to which paralleled is an exception, whereas AmE follows the general rule (travel/traveled). Similarly, BrE writes kidnapped and worshipped (but galloped and gossiped), while AmE may have kidnapped or kidnaped and worshipped or worshiped. There is some uncertainty with verbs ending in -s, BrE tending to double (bus/bussed, bias/biassed, focus/focussed) and AmE tending to stay single (bus/bused, focus/focused). Publishing houses may have their own preferences: Oxford University Press in Britain favours biased, focused. In AmE benefited is the only form used; in BrE, although it is the dominant form, benefitted also occurs.

Indicators of pronunciation

(1) In the past tense of a regular verb whose stem ends in a /d/ or /t/, an unstressed (that is, centralized) vowel is heard before the final /d/: needed, preceded, waited, hated. The same is true of an adjective distinguished from a past participle: an agèd man as opposed to aged 30; a learnèd professor as opposed to learned English quickly. This distinction is sometimes required in poetry for metrical reasons, when the appropriate pronunciation can be shown by means of a GRAVE ACCENT or an APOSTROPHE. So, in Shakespeare's Hamlet, damned has two full syllables in smiling, damnèd villain (1.5), but only one in A damn'd defeat (2.2). (2) If pronounced /t/, the inflection was formerly often written t: in early editions of Shakespeare, the phrase untimely ripped was spelt vntimely ript. (3) In the 18c, especially in private writing, the suffix -d was often preceded by an apostrophe to indicate an omitted silent e (ask'd, pass'd, shew'd).

Silent D

(1) In a few words, when d precedes or follows n, d is commonly no longer pronounced: handkerchief, handsome, and (with the exception of ScoE) Wednesday. (2) The d of the Latinate prefix ad- is silent before j: compare the pronunciations of ajar and adjacent.

Digraph DG

In the combination dg, the d serves to mark or emphasize the soft j-value of the following g (badge, judge: contrast bag, jug), and is the equivalent of doubling a single letter.

Epenthetic D

(1) A number of words have an epenthetic d after n: thunder (from Old English thunor: compare German Donner), and jaundice, astound, sound, from Old French jaunisse (Modern jaunise), estoné (Modern étonné), and soner (Modern sonner). (2) The d in admiral, advance, advice was inserted in Early Modern English in the belief that words like these were from Latin and should therefore contain the prefix ad-, although the forms in which they had come from French did not exhibit it: compare French amiral, avance, avis. Quasi-Latinate spellings with d became conventional, and pronouncing the d followed, even where the inserted letter was etymologically spurious: for example, admiral derives from Arabic amir (commander), and advance from Latin abante (from before: compare Italian avanti). Advice is from Old French a vis (abstracted from the phrase ce m'est a vis: It seems to me), which can ultimately be derived from Latin ad visum. See EPENTHESIS, G, HARD AND SOFT.

D¹ / dē/ (also d) • n. (pl. Dsor D's) 1. the fourth letter of the alphabet. ∎  denoting the fourth in a set of items, categories, sizes, etc. ∎  the fourth highest category of academic mark.2. (D) a shape like that of a capital D: [in comb.] the D-shaped handle. ∎  a loop or ring of this shape.3. (usu. D) Mus. the second note of the diatonic scale of C major. ∎  a key based on a scale with D as its keynote.4. the Roman numeral for 500.D² • abbr. ∎  Democrat or Democratic. ∎  depth (in the sense of the dimension of an object from front to back). ∎  Chem. dextrorotatory: D-glucose. ∎  (with a numeral) dimension(s) or dimensional: a 3-D model. ∎  (in tables of sports results) drawn. ∎  (on an automatic gearshift) drive. ∎  (in personal ads) divorced.• symb. ∎  Physics electric flux density. ∎  Chem. deuterium.

d • abbr. ∎  date. ∎  (in genealogies) daughter. ∎  day(s): orbital period: 687.0 d. ∎  deceased. ∎  deep. ∎  [in comb.] (in units of measurement) deci-. ∎  (in timetables) departs. ∎  (d.) died (used to indicate a date of death). ∎  divorced. ∎ Brit. penny or pence (of predecimal currency): £20 10s 6d. ∎ Chem. denoting electrons and orbitals possessing two units of angular momentum: d-electrons.• symb. ∎  Math. diameter. ∎  Math. denoting a small increment in a given variable: dy/dx.

d symbol for day
• symbol for deci- (prefix indicating 0.1, as in dB, decibel)
• Biochem., symbol for deoxyribonucleoside (preceding the nucleoside symbol, as in dT, thymidine)
• Physics, symbol for deuteron
• (ital.) Chem. dextrorotatory (as in d-tartaric acid)
• (ital.) symbol for diameter
• Music doh (in tonic sol-fa)
• Physics down (a quark flavour)
• (ital.) symbol for relative density
• (ital.) symbol for thickness
• Maths., indicating a small increment in a given variable or function (as in dy/dx)
• Physics, Chem., indicating the electron state l=2, where l is the orbital angular momentum quantum number
• indicating the fourth vertical row of squares from the left on a chessboard

'd • contr. of ∎  had: they'd already gone. ∎  would: I'd expect that.