Source : Webster's Revised Unabridged Dictionary (1913)

Tyrannic \Ty*ran"nic\ (?; 277), Tyrannical \Ty*ran"nic*al\, a.
   [L. tyrannicus, Gr. ?: cf. F. tyrannique. See {Tyrant}.]
   Of or pertaining to a tyrant; suiting a tyrant; unjustly
   severe in government; absolute; imperious; despotic; cruel;
   arbitrary; as, a tyrannical prince; a tyrannical master;
   tyrannical government. ``A power tyrannical.'' --Shak.

         Our sects a more tyrannic power assume.  --Roscommon.

         The oppressor ruled tyrannic where he durst. --Pope.
   -- {Ty*ran"nic*al*ly}, adv. -- {Ty*ran"nic*al*ness}, .

Source : WordNet®

tyrannic
     adj : of or relating to or associated with or resembling a
           dictatorship; "tyrannical suppression of liberty" [syn:
            {tyrannical}]