/ Dictionary / Index H high day: Meaning and Definition of Find definitions for: high' day" Pronunciation: [key] a holy or festal day. heyday. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. highdaddy high-definition television Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language