Illustration from 1908 Chambers's Twentieth Century. <b>Z</b>, the twenty-sixth and last letter in our alphabet, is derived through the Greek <i>zeta</i>, from <i>zayin</i>, the seventh Semitic letter—its sound a voiced sibilant, either a voiced <i>s</i> as in 'zeal,' or a voiced <i>sh</i> as in 'azure.'
Rev. Thomas Davidson 1856-1923 (<i>ed.</i>)
Chambers's Twentieth Century Dictionary of the English Language