Ḍād (ﺽ) is the fifteenth letter of the Arabic alphabet, one of the six letters not in the twenty-two akin to the Phoenician alphabet (the others being ṯāʾ, ḫāʾ, ḏāl, ẓāʾ, ġayn). In name and shape, it is a variant of ṣād. Its numerical value is 800 (see Abjad numerals). It is related to the Ancient North Arabian 𐪓, South Arabian 𐩳.
The letter symbol itself is a derivation, by addition of a diacritic dot, from ص ṣād (representing /sˤ/).
The Arabic chat alphabet, also known as Arabizi, Arabeezi, Arabish, Franco-Arabic or simply Franco (from French: franco-arabe) refer to the romanized alphabets for informal Arabic dialects in which Arabic script is transcribed or encoded into a combination of Latin script and Western Arabic numerals. These informal chat alphabets were originally used primarily by youth in the Arab world in very informal settings—especially for communicating over the Internet or for sending messages via cellular phones—though use is not necessarily restricted by age anymore and these chat alphabets have been used in other media such as advertising.
These chat alphabets differ from more formal and academic Arabic transliteration systems, in that they use numerals and multigraphs instead of diacritics for letters such as ṭāʾ (ط) or ḍād (ض) that do not exist in the basic Latin script (ASCII), and in that what is being transcribed is an informal dialect and not Standard Arabic. These Arabic chat alphabets also differ from each other, as each is influenced by the particular phonology of the Arabic dialect being transcribed and the orthography of the dominant European language in the area—typically the language of the former colonists, and typically either French or English.
The Arabic script has numerous diacritics, which include consonant pointing known as iʻjām (إِعْجَام, IPA: [ʔiʕdʒæːm]), and supplementary diacritics known as tashkīl (تَشْكِيل, IPA: [t̪æʃkiːl]). The latter include the vowel marks termed ḥarakāt (حَرَكَات, IPA: [ħæɾækæːt̪]; sg. حَرَكَة, ḥarakah, IPA: [ħæɾækæ]).
The Arabic script is a modified abjad, where all letters are consonants, leaving it up to the reader to fill in the vowel sounds. Short consonants and long vowels are represented by letters, but short vowels and consonant length are not generally indicated in writing. Tashkīl is optional to represent missing vowels and consonant length. Modern Arabic is always written with the i‘jām—consonant pointing—but only religious texts, children's books and works for learners are written with the full tashkīl—vowel guides and consonant length. It is, however, not uncommon for authors to add diacritics to a word or letter when the grammatical case or the meaning is deemed otherwise ambiguous. In addition, classical works and historical documents rendered to the general public are often rendered with the full tashkīl, to compensate for the gap in understanding resulting from stylistic changes over the centuries.
Tsade (also spelled ṣade, ṣādē, ṣaddi, ṣad, tzadi, sadhe, tzaddik) is the eighteenth letter of the Semitic abjads, including Phoenician ṣādē 𐤑, Hebrew ṣādī צ, Aramaic ṣāḏē 𐡑, Syriac ṣāḏē ܨ, Ge'ez ṣädäy ጸ, and Arabic ṣād ص. It is related to the Ancient North Arabian 𐪎, South Arabian 𐩮, and Ge'ez ጸ. The corresponding letter of the Ugaritic alphabet is 𐎕 ṣade.
Its oldest phonetic value is debated, although there is a variety of pronunciations in different modern Semitic languages and their dialects. It represents the coalescence of three Proto-Semitic "emphatic consonants" in Canaanite. Arabic, which kept the phonemes separate, introduced variants of ṣād and ṭāʾ to express the three (see ḍād, ẓāʾ). In Aramaic, these emphatic consonants coalesced instead with ʿayin and ṭēt, respectively, thus Hebrew ereṣ ארץ (earth) is araʿ ארע in Aramaic.