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

Strong bones also require nutrients like vitamin D, magnesium, vitamin K, protein, and omega-3 fatty acids. — Suchandrima Bhowmik, Health, 25 June 2026

This same three-tablespoon serving of hemp seeds will also give you about 9-10 grams of protein, healthy fats like omega-3s, and fiber, Manaker said. — Maggie O'Neill, Verywell Health, 25 June 2026

Chia, hemp and flaxseed oil capsules provide a third type of omega-3 called alpha-linolenic acid, or ALA, an antioxidant with the important job of turning food into energy. — Sandee Lamotte, CNN Money, 18 June 2026

Sardines, however, provide significantly higher levels of nutrients per serving, among them omega-3 fatty acids, selenium, vitamin B12, plus calcium if eating bone-in options (totally safe to eat, as the canning process softens them to the texture of very al dente pasta). — Rebecca Firkser, Bon Appetit Magazine, 11 June 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