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

Certain nutrients — including protein, fiber and long-chain fatty acids — can stimulate GLP-1 release. —Deirdre Bardolf, FOXNews.com, 7 Mar. 2026

Fish like salmon, cod, and tilapia offer choline along with the benefit of omega-3 fatty acids, which also support brain health. —Lauren Manaker, SELF, 5 Mar. 2026

These help signal satiety to the brain while producing beneficial short-chain fatty acids, such as butyrate, which support gut barrier function, immune regulation and metabolic health. —Hannah Coates, Vogue, 5 Mar. 2026

Going longer without eating also raises levels of circulating nonesterified fatty acids (NEFAs). —Stephanie Anderson Witmer, Health, 4 Mar. 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