The eleventh letter of the alphabet; commonly called زَاىٌ, and sometimes زَآءٌ, [and زًا, and زَا, (see زَاىٌ in art. زوى,)] and زَىٌّ, and زَىْ. (MF.) It is one of the letters termed مَجْهُورَة [or vocal, i. e. pronounced with the voice, and not with the breath only]; and of the letters termed أَسِلَيَّة, because proceeding from the tip of the tongue. (TA.) Az says that it is not conjoined with ص in any Arabic word. (TA.) It is substituted for س and for ص; as in يَزْدِلُ for يَسْدِلُ, and يَزْدُقُ for يَصْدُقُ: and in the Tes-heel it is said that it is sometimes interchanged [with س] after ج, as in جُسْتُ خِلَالَ الدِّيَارِ for جُزْتُ; and after ر, as in رَسَبَ and رَزَبَ: which interchange, accord. to MF, is said to be of the dial. of Kelb; or, as Et-Toosee says, of the dial. of 'Odhrah and Kaab and Benul-'Ambar. (TA.)

[As a numeral, ز denotes Seven.]