Definition of "phytochemical"

phytochemical

adjective
not comparable
1. Pertaining to the chemistry of plants.
  Quotations
  The plants used belonged to botanical families known to have little phytochemical significance.
  1985, Wade Davis, The Serpent and the Rainbow, Simon & Schuster, page 87
noun
plural phytochemicals
1. Any chemical substance characteristic of plants.
2. Any chemical or nutrient derived from a plant source; a phytonutrient.