D The fourth letter in the English alphabet occupies the same position in the Latin, Greek and Phoenician alphabets, which represent the preceding stages in its history. The Phoenician name Daleth is represented by the Greek Delta. In form D has varied throughout its career comparatively little. In the earliest Phoenician it is with slight variations; in most Greek dialects which has been adopted as the Greek literary form, but in others as e.g. the earliest Attic or . The form with the rounded back, which has passed from Latin into the languages of western Europe, was borrowed from the Greeks of S.W. Italy, but is widely spread also amongst the peoples of the Peloponnese and of northern Greece. It arises from a form like when the sides which meet to the right are written or engraved at one stroke. From a very early period one side of the triangle was often prolonged, thus producing a form which is characteristic of Aramaic from 800 B.C. In Greek this was avoided because of the likelihood of its confusion with , the oldest form of the symbol for r, but in the alphabets of Italy—which were borrowed from Etruscan—this confusion actually takes place. Etruscan had no sound corresponding to the symbol D (in inscriptions written from right to left, ), and hence used it as a by-form for , the symbol for r. The Oscans and Umbrians took it over in this value, but having the sound d they used for it the symbol for r ( in Umbrian, in Oscan).
The sound which D represents is the voiced dental corresponding to the unvoiced t. The English d, however, is not a true dental, but is really pronounced by placing the tongue against the sockets of the teeth, not the teeth themselves. It thus differs from the d of French and German, and in phonetic terminology is called an alveolar. In the languages of India where both true dentals and alveolars are found, the English d is represented by the alveolar symbol (transliterated ḍ). Etymologically in genuine English words d represents in most cases dh of the original Indo-European language, but in some cases an original t. In many languages d develops an aspirate after it, and this dh becomes then a voiced spirant (ð), the initial sound of there and that. This has occurred widely in Semitic, and is found also in languages like modern Greek, where δ, except after ν, is always spirant, δέν (= not) being pronounced like English then. As the mouth position for l differs from that for d only by the breath being allowed to escape past one or both sides of the tongue, confusion has arisen in many languages between d and l, the best-known being cases like the Latin lacrima as compared with the Greek δάκ–ρυ. The English tear and the forms of other languages show that d and not l is the more original sound. Between vowels in the ancient Umbrian d passed into a sound which was transliterated in the Latin alphabet by rs; this was probably a sibilant r, like the Bohemian ř. In many languages it is unvoiced at the end of words, thus becoming almost or altogether identical with t. As an abbreviation it is used in Latin for the praenomen Decimus, and under the empire for the title Divus of certain deceased emperors. As a Roman numeral (= 500) it is only the half of the old symbol (= 1000); this was itself the old form of the Greek φ, which was useless in Latin as that language had no sound identical with the Greek φ. (P. Gi.)