/ Dictionary / Index H high-definition television: Meaning and Definition of Find definitions for: high'-def•i•ni'tion tel'evision Pronunciation: (hī'def"u-nish'un), [key] a television system having twice the standard number of scanning lines per frame and producing a sharper image, and greater picture detail. Abbr.: HDTV Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. high day high-density 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