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

Breast milk also contains fatty acids like palmitic acid and oleic acid, which help to moisturize and strengthen the skin barrier, and Epidermal Growth Factor (EGF), which may aid in skin healing and regeneration. —Starr Bowenbank, People.com, 22 June 2025

The primary ingredients are almonds and peanuts, so the bar is high in protein and unsaturated fatty acids, but still less than 200 calories. —Bestreviews, Mercury News, 16 June 2025

It’s made with 20% pure shea butter, plus coconut oil, hemp seed oil, and a skin-nourishing blend of essential fatty acids and antioxidant vitamins C and E. —Symiah Dorsey, Southern Living, 15 June 2025

Visceral fat leeches fatty acids called adipokines or chemokines, which cause systemic inflammation in the body. —Andrea Muraskin, NPR, 15 June 2025

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