The Collaborative International Dictionary of English v.0.48:

Izzard \Iz"zard\, n. (Zool.)
   See Izard.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Izzard \Iz"zard\, n. [Formerly ezed, prob. fr. F. et z['e]de and
   z.]
   The letter z; -- formerly so called.

The Collaborative International Dictionary of English v.0.48:

Zed \Zed\, n. [F., probably through It. zeta, fr. L. zeta. See
   Zeta.]
   The letter Z; -- called also zee, and formerly izzard.
   "Zed, thou unnecessary letter!" --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

izzard
    n 1: 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]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "izzard":
   Z, apodosis, catastrophe, ceasing, cessation, coda, conclusion,
   consummation, crack of doom, culmination, curtain, curtains, death,
   decease, denouement, destination, destiny, doom, effect, end,
   end point, ending, envoi, epilogue, eschatology, expiration, fate,
   final solution, final twitch, final words, finale, finality, finis,
   finish, goal, last, last breath, last gasp, last things,
   last trumpet, last words, latter end, omega, payoff, period,
   peroration, quietus, resolution, resting place, stoppage,
   stopping place, swan song, term, terminal, termination, terminus,
   windup