flavonoid

noun fla·vo·noid \ ˈflā-və-ˌnȯid \

Definition of flavonoid

: 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

Recent Examples of flavonoid from the Web

The fruit — especially its skin — is rich in antioxidant flavonoids such as quercetin and anthocyanins (for red apples) that have been linked to cardio-protective effects.

— consumer reports, Washington Post, "From oatmeal to sardines, 7 foods that really can help hearts stay healthy," 7 May 2018
On the other hand, purple sweet potatoes have more anthocyanins, the flavonoid found in blueberries.

— caroline walder, Good Housekeeping, "Sweet Potatoes Are Officially One of the Best Carbs You Can Eat," 5 Mar. 2018
Research into the chemical makeup of marijuana is still new, but there are at least 160 cannabinoids and as many as 500 terpenes and flavonoids in the plant, all of which can be separated out, mixed, and matched.

— josh dean, Bloomberg.com, "America Is Giving Away the $30 Billion Medical Marijuana Industry," 7 Mar. 2018
Plus, the polyphenols, flavonoids, and carotenoids in black carrots may substantially defend against chronic disease.

— Good Housekeeping, "Why You Should Eat Carrots Every Single Day," 2 Mar. 2018
Cacao is particularly high in a kind of flavonoid called flavanols, which are especially beneficial for vascular health.

— ashleigh spitza, Milwaukee Journal Sentinel, "Chocolate is more than romantic - it's good for the heart," 14 Feb. 2018
The hips, like the petals, are high in flavonoids, those small but mighty antioxidant friends.

— christine buckley, Bon Appetit, "How to Swap Exotic Superfoods for the Local Stuff," 19 July 2017
Flavonoids in chocolate may improve blood vessel function, which can lower blood pressure and clotting.

— consumer reports, Washington Post, "Some food choices (chocolate!) really may help you age better," 9 July 2017
The second type of chemical is a class of flavonoid, or plant pigment molecule, called catechins.

— ben guarino, The Denver Post, "The tea plant has a whopper genome, four times that of coffee, scientists find," 2 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'flavonoid.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of flavonoid

flavone + -oid

NEW! Time Traveler

First Known Use: 1947

in the meaning defined above

See Words from the same year

Medical Dictionary

flavonoid

adjective fla·vo·noid \ ˈflāv-ə-ˌnȯid , ˈflav- \

medical Definition of flavonoid

: of, relating to, or being a flavonoid

flavonoid

noun

medical Definition of flavonoid

: 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, November 1999

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, 2007

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