/ Dictionary / Index B base level: Meaning and Definition of Find definitions for: base' lev"el Pronunciation: [key] — Geol. Geol. the lowest level to which running water can erode the land. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. baseless baseline Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language