Tyrant

1. v. i. To act like a tyrant; to play the tyrant; to tyrannical.
2. n. An absolute ruler; a sovereign unrestrained by law or constitution; a usurper of sovereignty.
3. n. Specifically, a monarch, or other ruler or master, who uses power to oppress his subjects; a person who exercises unlawful authority, or lawful authority in an unlawful manner; one who by taxation, injustice, or cruel punishment, or the demand of unreasonable services, imposes burdens and hardships on those under his control, which law and humanity do not authorize, or which the purposes of government do not require; a cruel master; an oppressor.
4. n. Any one of numerous species of American clamatorial birds belonging to the family Tyrannidae; — called also tyrant bird.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.