/ Dictionary / Index B blood serum: Meaning and Definition of Find definitions for: blood' se"rum Pronunciation: [key] serum (def. 1). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. blood sausage bloodshed 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