/ Dictionary / Index P primary xylem: Meaning and Definition of Find definitions for: pri'mary xy'lem Pronunciation: [key] — Bot. Bot. xylem derived directly from the growth of an apical meristem. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. primary wave primate Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language