د dāl called دال مـﮩمله or غيرمعجمه is the eighth letter of the Arabic, and the tenth of the Persian alphabet. In the representation of Hindī words by the letters of these alphabets, it denotes the Nāgarī द (da); or, with ه (he) subjoined, ध (dha). In the numerical application of the Arabic al- phabet, د (dāl) stands for four; hence, in al- manacks, it represents the fourth day of the week, Wednesday: it is, moreover, used in astronomy to denote the planet Mercury, or the sign Leo of the Zodiack. This letter, in Persian, may be changed to ت (te); as, in بتر for بدتر Worse: or, when the next preceding letter is ,و,ا, or ي, or is moveable by a short vowel, it may be converted to ذ (ẕāl); as استاذ for استاد A master, گنبذ for گنبد A dome: (see Lumsdenʼs Persian Gram. p. 24). And, in Arabic words of the measure افتعال, when ,ذ,د or ز is the first letter of the root, د (dāl) is substituted for the servile ت (te); as, in ازدحام from زحم.