/ Dictionary / Index B ballast line: Meaning and Definition of Find definitions for: bal'last line" Pronunciation: [key] — Naut. Naut. the level to which a vessel is immersed when in ballast. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ballast ballast pocket Related Content Daily Word Quiz: pundit Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language