Kamal ad-Din

Kamal ad-Din (Arabic: كمال‌ الدين, Kamāl ad-Dīn) is a male Muslim given name or surname (laqab in Arabic), meaning "perfection of the religion" in Arabic.

The name is formed from the elements kamāl (كمال‌), al- (الـ), and dīn (دين). It is often transliterated as Kamāl al-Dīn, but because the letter dāl (د, d) is a sun letter, the lām (ل, l) of al- assimilates into the first letter of dīn in pronunciation, resulting in a doubled consonant.

In Classical Arabic the pronunciation of the name changes depending on its function. Thus, the nominative case of the name is Kamaluddin (Kamālu’d-Dīn), the accusative case is Kamaladdin (Kamāla’d-Dīn), and the genitive case is Kamaliddin (Kamāli’d-Dīn).