/ Dictionary / Index B breast line: Meaning and Definition of Find definitions for: breast' line" Pronunciation: [key] — Naut. Naut. a mooring line securing a ship to that part of a pier alongside it. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. breasting breastpin Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language