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

Linoleic acid is a type of omega-6 fatty acid found in dairy, various meat products, and certain seed oils. —Lindsay Cook, Health, 10 Sep. 2025

Daikon seed oil steps in to smooth flyaways and add lightweight slip, while camelina oil ferment (a first in a hair-care brand) brings omega-3, 6, and 9 fatty acids for a radiant, light-catching finish. —Christa Joanna Lee, Allure, 10 Sep. 2025

Omega-3 fatty acids are important for everyone's health. —Mira Miller, Verywell Health, 9 Sep. 2025

That extra nourishment and moisture is thanks mostly to the omega’s long-chain fatty acids, which act primarily on the surface of the hair, protecting against friction and heat. —Philipp Wehsack, Vogue, 2 Sep. 2025

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