/ Dictionary / Index H half-line: Meaning and Definition of Find definitions for: half-line Pronunciation: (haf'līn", häf'-), [key] — n. Math. ray (def. 7b). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. half-light half-liter Related Content Daily Word Quiz: denizen Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language