: 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
At the same time, fruity esters such as ethyl acetate and isoamyl acetate are released, which enhance wine’s aroma.
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Mike Desimone and Jeff Jenssen, Robb Report, 27 Apr. 2025
In skin care products, topical vitamin C comes in two forms: as pure ascorbic acid or in its ester form, explains Dr. Zeichner.
—Catharine Malzahn, Glamour, 17 Apr. 2025
Most of the polymers incorporated a fair amount of lactic acid, which can also form ester bonds.
—John Timmer, Ars Technica, 17 Mar. 2025
One of those, called organophosphate ester, or OPFRs, was measured in the new research.
—Sandee Lamotte, CNN Money, 15 Apr. 2025
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Mike Desimone and Jeff Jenssen, Robb Report, 27 Apr. 2025
In skin care products, topical vitamin C comes in two forms: as pure ascorbic acid or in its ester form, explains Dr. Zeichner.
—Catharine Malzahn, Glamour, 17 Apr. 2025
Most of the polymers incorporated a fair amount of lactic acid, which can also form ester bonds.
—John Timmer, Ars Technica, 17 Mar. 2025
One of those, called organophosphate ester, or OPFRs, was measured in the new research.
—Sandee Lamotte, CNN Money, 15 Apr. 2025
See All Example Sentences for ester
Cite this Entry
“Ester.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ester. Accessed 5 Jun. 2025.
Copy CitationKids 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
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