What is the meaning of ض?

Arabic letter ḍād

The sixteenth letter of the Acehnese alphabet, written in the Arabic script.

The fifteenth letter of the Arabic alphabet, written in the Arabic script; preceded by ص (ṣ) and followed by ط (ṭ).

The twenty-sixth numeral symbol of the Arabic alphabet (traditional abjad order, used for list numbering), written in the Arabic script; preceded by ذ (ḏ) and followed by ظ (ẓ).

The twenty-eighth letter of the Balti alphabet, written in the Arabic script.

The twenty-eighth letter of the Burushaski alphabet, written in the Arabic script.

The fifteenth letter of the Hijazi Arabic alphabet, written in the Arabic script; preceded by ص (ṣād) and followed by ط (ṭāʔ).

The twenty-eighth letter of the Khowar alphabet, written in the Arabic script; preceded by ص and followed by ط.

A letter of the Old Ruthenian alphabet, written in the Arabic script.

The twentieth letter of the Xiao'erjing abjad, written in the Arabic script.

The twenty-sixth letter of the Kashmiri alphabet, written in the Arabic script; preceded by ص (s) and followed by ط (t).

The sixteenth letter of the Malay alphabet, written in the Arabic script.

The twenty-fifth letter of the Pashto alphabet, written in the Arabic script; preceded by ص and followed by ط.

The eighteenth letter of the Persian alphabet, called ضاد (zâd), ضوات (zwât) or ضواد (zwâd) and written in the Arabic script; preceded by ص and followed by ط.

The twenty-first letter of the Punjabi alphabet, written in the Shahmukhi script; preceded by ص (ṣwāt) and followed by ط (t̤ōē).

The thirty-second letter of the Sindhi alphabet, written in the Arabic script; preceded by ص and followed by ط.

The twenty-first letter of the Urdu alphabet, written in the Arabic script; preceded by ص and followed by ط.

Source: wiktionary.org