authoritarian

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Characterized by or favoring absolute obedience to authority, as against individual freedom.
• adjective Tending to tell other people what to do in a peremptory or arrogant manner. synonym: dictatorial.

from The Century Dictionary.

• Favoring the principle of authority, as opposed to that of individual freedom.
• noun One who supports the principle of authority, as opposed to that of individual freedom.

from the GNU version of the Collaborative International Dictionary of English.

• noun behaves like a tyrant.
• adjective characteristic of an absolute ruler or absolute rule; having absolute sovereignty; -- of governments or rulers
• adjective expecting unquestioning obedience: "he was imperious and dictatorial"; "the timid child of authoritarian parents"; "insufferably overbearing behavior toward the waiter"

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Of, or relating to, absolute obedience to an authority.
• adjective Characterised by a tyrannical obedience to an authority; dictatorial.
• adjective Tending to impose one's demands upon others as if one was an authority.
• noun One who commands absolute obedience to his or her authority.
• noun One who follows and is excessively obedient to authority.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• adjective expecting unquestioning obedience
• noun a person who behaves in a tyrannical manner
• adjective characteristic of an absolute ruler or absolute rule; having absolute sovereignty