Arabic definite article, meaning the. It often prefixes Arabic proper nouns, especially place-names; an example is Al-Jazirah (Arabic: The Island), the name of an interfluvial region in The Sudan. The article is often used in lowercase form, hence al-Jazirah. Reference works, including Encyclopdia Britannica, often alphabetize names beginning with al- under the main part of the name (thus, in the example, Jazirah, Al-). Thirteen Arabic lettersthe so-called sun letters, t, th, d, dh, r, z, s, sh, s, d, t, z, and nassimilate the l of al- in pronunciation; thus, Ash-Sham (the colloquial Arabic name of Damascus), not Al-Sham. Care must be taken to avoid confusing the definite article al- meaning the with the form Al, a different Arabic construction that is used to designate a family or tribal name. Al is invariate and does not elide; thus, Al Sa'ud, not As-Sa'ud. The form Al is always romanized with a capital letter, irrespective of its position in an English sentence.
AL-
Meaning of AL- in English
Britannica English vocabulary. Английский словарь Британика. 2012