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

Omega-3 fatty acids are essential fats that support brain, eye, heart, and skin health. — Lindsay Curtis, Verywell Health, 20 Aug. 2026

This process yields short-chain fatty acids, such as acetate, butyrate, and propionate, which serve as an energy source for cells lining the colon, strengthen the intestinal barrier, regulate inflammation, and influence systemic metabolism. — Encyclopedia Britannica, 19 Aug. 2026

These 13 branched-chain fatty acids were also really persistent. — Laura Baisas, Popular Science, 19 Aug. 2026

According to the National Institutes of Health, the human body cannot produce enough omega-3 fatty acids to support cellular health. — Bestreviews, Mercury News, 19 Aug. 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