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

The lush formula is incredibly hydrating thanks to burdock oil, which is rich in fatty acids and vitamins. —Reece Andavolgyi, InStyle, 27 Feb. 2026

The formula leans on fatty acids derived from castor oil to help hydrate the scalp and reinforce each strand, creating a good foundation for volume. —Michelle Rostamian, Allure, 27 Feb. 2026

These beta-glucans are metabolized by the gut microbiota into short-chain fatty acids (SCFAs), which then serve as an energy source for intestinal cells, support a healthy gut barrier, and help regulate inflammation. —Jillian Kubala, Health, 27 Feb. 2026

Why Salmon Is Good for Blood Pressure Salmon is a good source of omega-3 fatty acids that are great for blood pressure and heart health. —Vanessa Caceres, Verywell Health, 27 Feb. 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