Pronunciation: (tir'u-nīz"), [key]
—v., -nized, -niz•ing.
1. to exercise absolute power or control, esp. cruelly or oppressively (often fol. by over).
2. to govern despotically, cruelly, or oppressively.
3. to govern or reign as a tyrant.
to rule or govern tyrannically; treat oppressively. Also, esp. Brit.,tyr'an•nise".
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.