The fifteenth letter of the alphabet: called ضَادٌ: it is one of the letters termed مَجْهُورَة [or vocal, i. e. pronounced with the voice, and not with the breath only]; (TA;) and of the letters termed شَجْرِيَّة, ('Eyn, Mgh, TA,) from الشَّجْرُ, which is the place of the opening of the mouth: ('Eyn, Mgh, TA on the letter ج:) its place of utterance is from the extremity of the tongue [extended so as to reach] to the part next to the [lateral teeth called] أَضْرَاس; and it is more usually pronounced from the left side than from the right: the vulgar [sometimes] pronounce it as ظَآء, making its place of utterance to be between the extremity of the tongue and the central incisors, which pronunciation is peculiar to a dialect, as mentioned by Fr on the authority of El-Fadl: he says [also]

that some of the Arabs substitute it for ظَآء, saying ضَهْر for ظَهْر; but that the doing thus, though allowable in speech, is not allowable in the reciting of the Book of God, which follows the rule, or usage, of the Prophet: (Msb in art. ضود:) or its place of utterance is from the foremost part of the edge of the tongue and the part next to the اضراس; and it has no sister [or analogue] accord. to Sb; but accord. to the 'Eyn, it is a sister of ذ and ث, and these three letters are termed لِثَوِيَّة [or gingival], because proceeding from the gum; the substitution of any of these, however, for another of them, vitiates prayers: (Mgh:) it is of the class termed الحُرُوفُ المُسْتَعْلِيَةُ: (L in art. ضود:) and is a letter peculiar to the Arabs, (L and K in that art.,) accord. to the general and correct opinion; (TA in that art.;) [whence the saying of Mohammad, أَنَا أَفْصَحُ مَنْ نَطَقَ بِالضَّادِ I am the most chaste in speech of those who have pronounced the letter dád; i. e., of the Arabs, agreeably with another saying, ascribed to him, mentioned voce بَيْدَ;] or it is a letter rarely occurring in the language of any other people. (L in that art.)

b2: It is always a radical letter; and is [said to be] not substituted for another letter; (L in art. ضود;) [but it is so substituted in some cases of إِدْغَام, as, for instance, for the ل of the article ال, and in يَضَّرَّعُ for يَتَضَرَّعُ, and the like; and] it is sometimes substituted for ص, as in مَضَّ الرُّمَّانَةَ for مَصَّهَا, as Ibn-Osfoor says, and Ks mentions مَنَاضٌ for مَنَاصٌ; (TA;) and also for ل, as Ibn-Málik says

in the Tes-heel, an instance of which is رَجُلٌ جَضْدٌ for جَلْدٌ, mentioned by J; (MF, TA;) and sometimes it is changed into ل, as in the instance of اِلْطَجَعَ for اِضْطَجَعَ. (S and L &c. in art. ضجع.)

A2: [As a numeral, it denotes Eight hundred.]