Begadkefat (also begedkefet) is the name given to a phenomenon of lenition affecting the non-emphatic stop consonants of Biblical Hebrew and Aramaic when they are preceded by a vowel and not geminated. The name is also given to similar cases of spirantization of post-vocalic plosives in other languages; for instance, in the Berber language of Djerba. Celtic languages have a similar system. The name of the phenomenon is made up of these six consonants, mixed with haphazard vowels for the sake of pronunciation: BeGaDKePaT. The Hebrew term (Modern Hebrew /ˌbeɡedˈkefet/) denotes the letters themselves (rather than the phenomenon of spirantization). Begedkefet spirantization developed sometime during the lifetime of Biblical Hebrew under the influence of Aramaic. Its time of emergence can be found by noting that the Old Aramaic phonemes θ, ð disappeared in the 7th century BC. During this period all six plosive / fricative pairs were allophonic. In Modern Hebrew, Sephardi Hebrew, and most forms of Mizrahi Hebrew, three of the six letters, (bet), (kaf) and (pe) each still denotes a stop–fricative variant pair; however, in Modern Hebrew these variants are no longer purely allophonic (see below). Although orthographic variants of (gimel), (dalet) and (tav) still exist, these letters' pronunciation always remains acoustically and phonologically indistinguishable. In Ashkenazi Hebrew and in Yiddish borrowings from Ashkenazi Hebrew, without dagesh still denotes a fricative variant s (under the influence of Judeo-German, aka Yiddish) which diverged from Biblical/Mishnaic θ. The only extant Hebrew pronunciation tradition to preserve and distinguish all begadkefat letters is Yemenite Hebrew; however, in Yemenite Hebrew the sound of gimel with dagesh is a voiced palato-alveolar affricate d͡ʒ (under the influence of Judeo-Yemeni Arabic), which diverged from Biblical/Mishnaic ɡ.