/ Dictionary / Index B blood level: Meaning and Definition of Find definitions for: blood' lev"el Pronunciation: [key] the amount of a substance, as cholesterol, alcohol, or triglycerides, circulating in the bloodstream: often expressed as a percent or in milligrams or micrograms per deciliter of blood. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. bloodletting blood lily 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