Of tyrannical character or quality; given to or marked by tyranny; harshly despotic.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. marked by unjust severity or arbitrary behavior
Word Usage
"But then, any Middle Eastern country, no matter how tyrannous, which is willing to obey Washington (and perhaps tacitly support Israeli crimes against the Palestinians) is ipso facto considered "moderate"."