Kingbird meaning

kĭngbûrd

Any of various flycatchers of the genus Tyrannus found throughout the Americas, especially T. tyrannus.

noun

Any of several aggressive tyrant flycatchers (genus Tyrannus) of the U.S. and Canada.

noun

A group of large insectivorous passerine birds of the genus Tyrannus.

noun

Origin of kingbird

From their habit of aggressively defending their territories by chasing away other birds

From American Heritage Dictionary of the English Language, 5th Edition
king +‎ bird

From Wiktionary