plant hormone

noun

: 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

Examples of plant hormone in a Sentence

Recent Examples on the Web

Ethylene is a plant hormone that triggers fruit to ripen, according to Deering. —Olivia McIntosh, Martha Stewart, 3 Mar. 2026

When cold treatment is cut short, the development of plant hormones that regulate flower height is disrupted as well. —Markis Hill, Kansas City Star, 25 Feb. 2026

During ripening, bananas naturally produce ethylene gas, a plant hormone that helps convert starches into sugars, softens the texture, and deepens the color of the bananas. —Katie Rosenhouse, Southern Living, 31 Dec. 2025

Some even produce plant hormones. —Anna Marija Helt, JSTOR Daily, 17 Sep. 2025

Word History

First Known Use

1932, in the meaning defined above

Rhymes for plant hormone

• acetone
• anglophone
• baritone
• bourguignon
• buspirone
• chaperon
• chaperone
• cobblestone
• collarbone
• cornerstone
• cortisone
• dictaphone

Kids Definition

plant hormone

noun

: a substance other than food that in small amounts changes one of the life processes of a plant

especially : one made by the plant itself and acting somewhere other than at the site where it is produced

Medical Definition

plant hormone

noun

ˈplant- 

: 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