v. i. [ imp. & p. p. Tyrannized p. pr. & vb. n. Tyrannizing ] [ Cf. F. tyranniser, Gr. tyranni`zein to take the part of tyrants. ] To act the tyrant; to exercise arbitrary power; to rule with unjust and oppressive severity; to exercise power over others not permitted by law or required by justice, or with a severity not necessary to the ends of justice and government; as, a prince will often tyrannize over his subjects; masters sometimes tyrannize over their servants or apprentices. [ 1913 Webster ]

v. t. To subject to arbitrary, oppressive, or tyrannical treatment; to oppress. [ 1913 Webster ]