/ Dictionary / Index X xenobiotic: Meaning and Definition of Find definitions for: xen•o•bi•ot•ic Pronunciation: (zen"u-bī-ot'ik, -bē-, zē"nu-), [key] — n. a chemical or substance that is foreign to an organism or biological system. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. xeno- Xenocrates Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language