It is hypothesized that the original pronunciation of the letter was a pharyngealised lateral fricative /ɮˤ/. The sound that was represented the letter ḍād in the Arabic alphabet when it was introduced is somewhat uncertain, most likely being introduced on late 7th to early 8th centuries. Early on, its sound was merged with ظ(ẓ)/ðˤ/, a merger that is reflected in all colloquial dialects. In dialects with stopping of dental fricatives, both were then shifted further to /dˤ/. When the ability to produce the sound /ɮˤ/ waned some time after its loss from actual speech, the Quran readers reassigned the stop /dˤ/ to ض(ḍ) in order to maintain its distinction from ظ(ẓ).
The twenty-sixth letter in traditional abjad order, which is used in place of numerals for list numbering (abjad numerals). It is preceded by ذ(ḏ) and followed by ظ(ẓ).
The eighteenth letter of the Perso-Arabic alphabet. It is preceded by ص and followed by ط. Its name is ضاد(zâd), In Dari it may also go by the names ضوات(zwât) and ضواد(zwâd, zwâd).