Ad-Din


Ad-Din, a suffix component of some Arabic names, meaning "the religion/faith/creed", e.g. Saif al-Din.
The Arabic spelling in its standard transliteration is ad-Din, due to the phonological rules involving "sun letter", the Arabic letter د is assimilated letter of the ِArabic definite article ال. The first noun of the compound must have the ending -u which according to the assimilation rules in Arabic - names in general is in the nominative case, assimilates the following a-, thus manifesting into ud-Din in Classical and Modern Standard Arabic.
However, all the modern Arabic vernaculars lack the noun endings, thus the vowel of the definite article in them is pronounced in full as either a or e. At the same time the Arabic short vowel u is rendered as short o in Persian, thus od-din.
So in practice romanizations of Arabic names containing this element may vary greatly, including:
Examples of names including this element are:
In modern times in English-speaking environments the name Uddin has sometimes been used as if it was a separate surname. An example is: