omega-3

adjective

ome·​ga-3 ō-ˈmā-gə-ˈthrē 

-ˈmē-, 

-ˈme- 

: being or composed of polyunsaturated fatty acids that have the final double bond in the hydrocarbon chain between the third and fourth carbon atoms from the end of the molecule opposite that of the carboxyl group and that are found especially in fish, fish oils, green leafy vegetables, and some nuts and vegetable oils compare omega-6

omega-3 noun

Examples of omega-3 in a Sentence

Recent Examples on the Web

Salmon contains omega-3 fats that may offer additional benefits for insulin sensitivity and heart health. — Lindsey Desoto, Health, 20 July 2026

My breakfast was smoked trout and a cup of sheep’s milk yogurt topped with omega-3 oil. — Marisa Meltzer, Vanity Fair, 17 July 2026

Common ingredients include magnesium glycinate for sleep, creatine for brain fog and muscle support, omega-3s, adaptogens, and cortisol or stress complexes. — Hanna Wickes, Fort Worth Star-Telegram, 16 July 2026

The Mediterranean diet is naturally rich in anti-inflammatory nutrients, including omega-3 fatty acids from fish and antioxidants called polyphenols found in extra-virgin olive oil. — Khloe Quill, FOXNews.com, 15 July 2026

Word History

First Known Use

1967, in the meaning defined above

Medical Definition

omega-3

adjective

ome·​ga-3 -ˈthrē 

variants also Omega-3

: being or composed of polyunsaturated fats that have the first double bond in the hydrocarbon chain occurring between the third and fourth carbon atoms from the end of the molecule most distant from the carboxylic acid group and that are found especially in fish, fish oils, green leafy vegetables, and some nuts and seeds

The two main omega-3 fatty acids in fish oil … appear to reduce the risk of dying from sudden cardiac arrest by about 30 percent.

—Nutrition Action Health Letter

compare omega-6

omega-3 noun

also Omega-3

Some plants, such as linseed, naturally produce an omega-3 called alpha-linolenic acid (ALA), and one way to increase the amount of omega-3 in our diet is to eat these plants …

—Andy Coghlan, New Scientist