Source : Webster's Revised Unabridged Dictionary (1913)

Z \Z\ (z[=e]; in England commonly, and in America sometimes,
   z[e^]d; formerly, also, [i^]z"z[e^]rd)
   Z, the twenty-sixth and last letter of the English alphabet,
   is a vocal consonant. It is taken from the Latin letter Z,
   which came from the Greek alphabet, this having it from a
   Semitic source. The ultimate origin is probably Egyptian.
   Etymologically, it is most closely related to s, y, and j; as
   in glass, glaze; E. yoke, Gr. ?, L. yugum; E. zealous,
   jealous. See Guide to Pronunciation, [sect][sect] 273, 274.

Source : WordNet®

Z
     n 1: the ending of a series or sequence; "the Alpha and the
          Omega, the first and the last, the beginning and the
          end"--Revelation [syn: {omega}]
     2: the 26th letter of the Roman alphabet; "the British call Z
        zed and the Scots call it ezed but Americans call it zee";
        "he doesn't know A from izzard" [syn: {zee}, {zed}, {ezed},
         {izzard}]

Source : Free On-Line Dictionary of Computing

Z++
     
         An {object-oriented} extension of {Z}.
     
        ["Z++, an Object-Oriented Extension to Z", Lano, Z User
        Workshop, Oxford 1990, Springer Workshops in Computing, 1991,
        pp.151-172].
     
        (1995-04-22)

Z
     
        /zed/  1. (After {Zermelo-Frankel set
        theory}) A {specification language} developed by the
        {Programming Research Group} at Oxford University around 1980.
        Z is used for describing and modelling computing systems.  It
        is based on {axiomatic set theory} and {first order predicate
        logic}.  Z is written using many non-{ASCII} symbols.  It was
        used in the {IBM} {CICS} project.
     
        See also {Z++}.
     
        ["Understanding Z", J.M. Spivey, Cambridge U Press 1988].
     
        2.  A {stack}-based, complex arithmetic
        {simulation} language from {ZOLA Technologies}.
     
        (1995-08-11)