From WordNet (r) 3.0 (2006):
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, Z]
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: Z, z, zee, zed,
ezed, izzard]