Definitionen
1.NounArabic diacritic similar in appearance to a tilde. Over an alif (آ (ʔā) "alif maddah"), it indicates glottal stop, /ʔ/, followed by a long /aː/. The diacritic is not used separately, only over alif. Alif maddah can appear in the beginning: آسِف (ʔāsif) or in the middle of a word: قُرْآن (qurʔān).
2.NounIn the Qur'an, it indicates an extra long vowel and can appear over any long vowel.
3.NounIn Persian the letter is used only in the beginning of a word with a long /aː/: آمدن (âmadan).