/ Dictionary / Index G great blue heron: Meaning and Definition of Find definitions for: great' blue' her'on Pronunciation: [key] a large American heron, Ardea herodias, having bluish-gray plumage. See illus. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. great black-backed gull great blue shark Related Content Daily Word Quiz: censure Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language