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

Your Levels of Inflammation May Be Reduced Both omega-3 fatty acids and omega-3s lower inflammation markers in the body, such as interleukin-6 and C-reactive protein. —Megan Nunn, Verywell Health, 30 Jan. 2026

Babassu oil contains fatty acids and antioxidants that help soothe skin, while olive oil and Jojoba are deeply hydrating and help to lock in the skin's moisture. —Melony Forcier, InStyle, 30 Jan. 2026

How Omega-3s Affect Heart Health Omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), help regulate inflammation throughout the body, supporting healthy blood vessel function, an essential component of heart health. —Jillian Kubala, Health, 30 Jan. 2026

Brezavscek points barrier-supportive formulas, such as fatty acids, peptides, ceramides, hyaluronic acid, and niacinamide are key to soothe skin and restore its lipid balance. —Kiana Murden, Vogue, 29 Jan. 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