/ Dictionary / Index P platinum black: Meaning and Definition of Find definitions for: plat'inum black' Pronunciation: [key] — Chem. Chem. a black powder consisting of very finely divided metallic platinum, used as a catalyst, esp. in organic synthesis. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. platinum platinum blonde Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language