/ Dictionary / Index I inbounds line: Meaning and Definition of Find definitions for: in'bounds' line" Pronunciation: [key] — Football. Football. one of two broken lines, parallel to the sidelines and running the length of the field, to which the ball is brought when it goes beyond the sidelines. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. inbounds in-box Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language