flavonoid

noun

fla·​vo·​noid ˈflā-və-ˌnȯid 

: any of a large group of typically biologically active water-soluble plant compounds (such as the anthocyanins and flavones) that include pigments ranging in color from yellow to red to blue and occur especially in fruits, vegetables, and herbs (such as grapes, citrus fruits, peppers, and dill)

Flavonoids are effective scavengers of free radicals in the test tube (in vitro). However, even with very high flavonoid intakes, plasma and intracellular flavonoid concentrations in humans are likely to be 100 to 1000 times lower than concentrations of other antioxidants …

—Jane Higdon

The rich palette of dyes in butterflies' wings are all derived from chemicals called flavonoids, which the insects cannot make themselves and must sequester from their food plants.

—Nicholas Wade

see bioflavonoid

Examples of flavonoid in a Sentence

Recent Examples on the Web

The essential oils, flavonoids, and other constituents go into the beverage that is the foundation of a $300 billion global enterprise. —Wade Davis, Rolling Stone, 6 Apr. 2025

While cannabis does contain hundreds of chemical compounds—including cannabinoids, terpenes, and flavonoids—the exact number fluctuates depending on the strain and growing conditions. —Matt Rozo, Mercury News, 3 Apr. 2025

Honey and maple syrup contain antioxidants, including flavonoids and phenolic acids. —Jillian Kubala, Health, 3 Mar. 2025

Full-spectrum and broad-spectrum CBD tinctures contain either all or most of the cannabinoids found in the hemp plant, along with terpenes and flavonoids. —Bestreviews, Chicago Tribune, 25 Feb. 2025

Word History

Etymology

flavone + -oid

First Known Use

1947, in the meaning defined above

Medical Definition

flavonoid

1 of 2 adjective

fla·​vo·​noid ˈflāv-ə-ˌnȯid  ˈflav- 

: of, relating to, or being a flavonoid

flavonoid

2 of 2 noun

: any of a large group of typically biologically active, water-soluble, plant compounds (such as the flavones) that include pigments ranging in color from yellow to red to blue and occur especially in fruits, vegetables, and herbs (such as grapes, citrus fruits, peppers, and dill)

Tea contains substances called catechins (tea flavonoids) that may protect against heart disease and even cancer.

—UC Berkeley Wellness Newsletter

Flavonoids are effective scavengers of free radicals in the test tube (in vitro). However, even with very high flavonoid intakes, plasma and intracellular flavonoid concentrations in humans are likely to be 100 to 1000 times lower than concentrations of other antioxidants …

—Jane Higdon, An Evidence-Based Approach to Dietary Phytochemicals

Note: Flavonoids are polyphenolic 15-carbon compounds with a basic structure consisting of two benzene rings joined by a chain of 3 carbons.

see bioflavonoid