ester

noun

es·​ter ˈe-stər 

: any of a class of often fragrant organic compounds that can be represented by the formula RCOOR′ and that are usually formed by the reaction between an acid and an alcohol with elimination of water

Examples of ester in a Sentence

Recent Examples on the Web

Top ingredients include synthetic beeswax and jojoba esters for binding and thickening without leaving a greasy texture. —Clint Davis, People.com, 1 Oct. 2024

What’s more, jojoba esters keep the hair smooth in the face of humidity, while phytantriol both prevents color from washing out and serves as a heat protectant. —Jenny Berg, Vogue, 11 Sep. 2024

In animal foods, vitamin A is found in the form of retinol and retinyl esters. —Jillian Kubala, Health, 16 Sep. 2024

Meanwhile, retinyl ester is the least potent (and most stable) form of vitamin A out of the three. —Venus Wong, refinery29.com, 5 Sep. 2024

Word History

Etymology

German, from Essigäther ethyl acetate, from Essig vinegar + Äther ether

First Known Use

circa 1852, in the meaning defined above

Kids Definition

ester

noun

es·​ter ˈes-tər 

: an organic compound formed by the reaction between an acid and an alcohol

Medical Definition

ester

noun

es·​ter ˈes-tər 

: any of a class of often fragrant compounds that can be represented by the formula RCOOR′ and that are usually formed by the reaction between an acid and an alcohol usually with elimination of water