Meaning of xenobiotic

xen•o•bi•ot•ic

Pronunciation: (zen"u-bī-ot'ik, -bē-, zē"nu-), [key]
— n.
  1. 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.