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

That includes helping reduce inflammation and oxidative stress, as well as providing brain-boosting omega-3 and omega-6 fatty acids. —Kathleen Felton, Time, 9 June 2026

My current go-to is RŌZ Hair’s Willow Glen Pre-Wash Treatment Oil, which is naturally rich in fatty acids thanks to its macadamia oil base. —Conçetta Ciarlo, Vogue, 8 June 2026

Research comparing obese and non-obese horses has found that their serum lipid profile closely mirrors that of obese humans, with the same elevations in free fatty acids and the same patterns of fatty acid accumulation associated with inflammation. —Joshua Moen, STAT, 8 June 2026

This snack is rich in protein to keep you full and omega-3 fatty acids for the health benefits. —Carrie Madormo, Verywell Health, 8 June 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