ester
[C/U] Both
pl: esters
This term is primarily used in organic chemistry to describe a specific functional group. It is most commonly associated with the pleasant, sweet scents found in nature, such as those in apples, bananas, or pears, making it a key word in the fragrance and flavor industries. In a laboratory or industrial setting, the term carries a technical, precise connotation. It is rarely used in casual conversation unless the speaker is discussing chemistry, perfumes, or the biological process of lipid formation.
Countable when referring to a specific chemical species like an ethyl acetate ester. Uncountable when referring to the general class of chemical compounds.