Definition from Wiktionary, the free dictionary
sun letter (plural sun letters)
- One of fourteen Arabic letters that cause the "L" of a preceding definite article 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: الصّين. The fourteen sun letters are:
- In Moroccan and Levantine Arabic, ج is also considered a sun letter, and assimilates with the definite article, as it is pronounced IPA(key): /ʒ/, not IPA(key): /dʒ/.