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

While the small fish are certainly present, offering welcome saltiness (not to mention protein, omega-3s, and potential complexion-enhancing nutrients), your taste buds are not going to be overwhelmed by them. —Rebecca Firkser, Bon Appetit Magazine, 11 June 2026

Fatty fish like salmon, tuna, and mackerel have some of the highest levels of omega-3 fatty acids in food. —Kathleen Felton, Time, 9 June 2026

This snack is rich in protein to keep you full and omega-3 fatty acids for the health benefits. —Carrie Madormo, Verywell Health, 8 June 2026

Fish provides high-quality complete protein, omega-3 fatty acids, vitamin D and B12. —Scott Travers, Forbes.com, 6 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