/ Dictionary / Index P polysome: Meaning and Definition of Find definitions for: pol•y•some Pronunciation: (pol'ē-sōm"), [key] — n. Biol. a complex of ribosomes strung along a single strand of messenger RNA that translates the genetic information coded in the messenger RNA during protein synthesis. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. polysepalous polysomnogram Related Content Daily Word Quiz: pugilist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language