The Collaborative International Dictionary of English v.0.48:

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.
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         Our sects a more tyrannic power assume.  --Roscommon.
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         The oppressor ruled tyrannic where he durst. --Pope.
   [1913 Webster] -- Ty*ran"nic*al*ly, adv. --
   Ty*ran"nic*al*ness, .
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