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

According to Pasquariello, avocados are rich in omega-3 fatty acids, which help fight inflammation. —Kirsten Nunez, Martha Stewart, 13 Jan. 2026

Sardines Fish, such as sardines, are rich in protein and omega-3 fatty acids. —Merve Ceylan, Health, 12 Jan. 2026

Formulated with omega-3 and omega-6 fatty acids plus antioxidant-rich botanicals, this facial oil targets dryness and loss of elasticity for softer, more resilient skin. —Colleen Sullivan, InStyle, 10 Jan. 2026

Flaxseeds Are Very Rich in Omega-3s Flaxseeds are one of the best plant sources of alpha-linolenic acid (ALA), a type of omega-3. —Morgan Pearson, Verywell Health, 9 Jan. 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