The letter is dalet in the modern Israeli Hebrew pronunciation (see Tav (letter)). Dales is still used by many Ashkenazi Jews and daleth by some Jews of Middle-Eastern background, especially in the diaspora. In some academic circles, it is called daleth, following the Tiberian Hebrew pronunciation. It is also called daled. The ד like the EnglishD represents a voiced alveolar stop. Just as in English, there may be subtle varieties of the sound that are created when it is spoken.
The letter dalet, along with the He (and very rarely Gimel) is used to represent the Names of God in Judaism. The letter He is used commonly, and the dalet is rarer. A good example is the keter (crown) of a tallit, which has the blessing for donning the tallit, and has the name of God usually represented by a dalet. A reason for this is that the He is used as an abbreviation for HaShem "The Name" and the dalet is used as a non-sacred way of referring to God.
Dalet as a prefix in Aramaic (the language of the Talmud) is a preposition meaning "that", or "which", or also "from" or "of"; since many Talmudic terms have found their way into Hebrew, one can hear dalet as a prefix in many phrases (as in MitzvahDoraitah; a mitzvah from the Torah.)
in modern Hebrew the frequency of the usage of dalet, out of all the letters, is 2.59%.
In the Syriac alphabet, the fourth letter is ܕ — Dolath in western pronunciation, Dalath and Daled in eastern pronunciation (ܕܵܠܵܬ). It is one of six letters that represents two associated sounds (the others are Bet, Gimel, Kaph, Pe and Taw). When Daled/Dolath has a hard pronunciation (qûššāyâ) it is a [d]. When Dalad/Dolath has a soft pronunciation (rûkkāḵâ) it is traditionally pronounced as a [ð]. The letter is very common in Syriac as it is often attached to the beginning of words as the relative pronoun.
Daled/Dolath is always written with a point below it to distinguish it from the letter Resh (ܪ), which is identical apart from having a point above. As a numeral, Dalad/Dolath stands for the number four. With various systems of dots and dashes, it can also stand for 4,000 and 40,000.