Tyrant /(tī"rant)/

Tyr·ant

Tyrant

An absolute ruler; a sovereign unrestrained by law or constitution; a usurper of sovereignty.
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.
Love, to a yielding heart, is a king, but to a resisting, is a tyrant.
— Sir P. Sidney.
Any one of numerous species of American clamatorial birds belonging to the family Tyrannidae; -- called also tyrant bird. (Zool.)

Tyrant flycatcher: any one of numerous species of tyrants which have a flattened bill, toothed at the tip, and resemble the true flycatchers in habits. The Acadian flycatcher (Empidonax Acadicus) and the vermilion flycatcher (Pyrocephalus rubineus) are examples.
Tyrant shrike: any one of numerous species of American tyrants of the genus Tyrannus having a strong toothed bill and resembling the shrikes in habits. The kingbird is an example.

v. i.