/ Dictionary / Index B blood platelet: Meaning and Definition of Find definitions for: blood' plate"let Pronunciation: [key] any of numerous, minute, protoplasmic bodies in mammalian blood that aid in coagulation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. blood plasma blood poisoning Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language