/ Dictionary / Index P polybasite: Meaning and Definition of Find definitions for: pol•y•ba•site Pronunciation: (pol"ē-bā'sīt, pu-lib'u-sīt"), [key] — n. a blackish mineral, AgSbS: a minor ore of silver. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. polybasic Polybius Related Content Daily Word Quiz: lunar Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language