sun letter

One of fourteen Arabic letters that cause the "L" of a preceding definite article اَل (al-) to be assimilated in pronunciation. The sun letter suppresses the sound of the "L" and then geminates: al + ṣīn = aṣ-ṣīn. The effect of the sun letter is limited to pronunciation and does not affect the spelling, except that a shadda may be written over the sun letter and in the fully vocalised spelling lām lacks any diacritics: الصِّين (aṣ-ṣīn). The fourteen sun letters are ت (t), ث (ṯ), د (d), ذ (ḏ), ر (r), ز (z), س (s), ش (š), ص (ṣ), ض (ḍ), ط (ṭ), ظ (ẓ), ل (l), ن (n). Phonetically, they represent coronal consonants.