Medical Definition of plant hormone
: an organic substance other than a nutrient that in minute amounts modifies a plant physiological process; especially : one produced by a plant and active elsewhere than at the site of production—called also phytohormone
Learn More about plant hormone
Dictionary: Definition of "plant hormone"
Seen and Heard
What made you want to look up plant hormone? Please tell us where you read or heard it (including the quote, if possible).