From Proto-Semitic *ʾil- with a vocative suffix ـَاه (-āh) which is else only sporadically attested in Arabic but has left its trace in the -ā vocatives of أَب (ʔab, “father”), أَخ (ʔaḵ, “brother”), حَم (ḥam, “father-in-law”). Forms a root ء ل ه (ʔ l h).