ض ẓad called ضاد معجمه and ضاد منقوطه the fif- teenth letter of the Arabic alphabet, does not occur in Persian, nor is there any corresponding letter in Sanskrit. In Persia and Hindū- stān its pronunciation is hardly distinguished from that of ز; but, in Arabia it is a mixed sound of d, th, and w, only to be acquired from natives of that country. In the notation of numbers by the Arabic letters, it stands for 800. It is one of the radical letters. The د of Per- sian words, when they are introduced into Ara- bic, is often changed into this letter, as ضحاک for ده آک See under ح. When three of these letters meet together, as in تقضّض the darting of a hawk upon his prey, the last is changed into ي, as تقضي. And in verbs of the measure افتعال the servile ت after this letter is changed to ط or to ض as اضطراب or اضّراب from ضرب.
