fatty acid

noun

1

: any of numerous saturated aliphatic monocarboxylic acids C_nH_2n+1COOH (such as acetic acid) including many that occur naturally usually in the form of esters in fats, waxes, and essential oils

2

: any of the saturated or unsaturated monocarboxylic acids (such as palmitic acid) usually with an even number of carbon atoms that occur naturally in the form of glycerides in fats and fatty oils

Examples of fatty acid in a Sentence

Recent Examples on the Web

What experts say about meal times and health Goodson adds that foods rich in omega-3 fatty acids, including walnuts, salmon and mackerel, also support heart health in other important ways. —Daryl Austin, USA Today, 7 Feb. 2026

Packed with vitamin D, B12 and omega-3 fatty acids, as well as essential minerals including iodine, selenium, iron, calcium, and potassium, the oily fish is suddenly being feted as the secret to glowy skin. —Ranyechi Udemezue, Vogue, 6 Feb. 2026

Walnuts are a better source of alpha-linolenic acid (ALA), an omega-3 fatty acid that provides anti-inflammatory benefits for heart and brain health. —Jillian Kubala, Health, 6 Feb. 2026

Camelina, rosehip, sunflower, and sea buckthorn oils add omega fatty acids and antioxidants to support elasticity and suppleness, while vitamin E provides an extra layer of antioxidant protection for skin that’s feeling thin or dry. —Christa Joanna Lee, Allure, 5 Feb. 2026

Word History

First Known Use

1838, in the meaning defined at sense 1

Rhymes for fatty acid

• antacid
• placid

Kids Definition

fatty acid

noun

: any of numerous acids that contain only carbon, hydrogen, and oxygen and occur naturally in fats and various oils

Medical Definition

fatty acid

noun

1

: any of numerous saturated aliphatic acids C_nH_2n+1COOH (as lauric acid) containing a single carboxyl group and including many that occur naturally usually in the form of esters in fats, waxes, and essential oils

2

: any of the saturated or unsaturated organic acids (as palmitic acid) that have a single carboxyl group and usually an even number of carbon atoms and that occur naturally in the form of glycerides in fats and fatty oils