noun ester An organic compound made by replacing the hydrogen of an acid by an alkyl or other organic group. Many naturally occurring fats and essential oils are esters of fatty acids. 1
noun ester chemical compound 1
noun ester any of a class of compounds produced by reaction between acids and alcohols with the elimination of water. Esters with low molecular weights, such as ethyl acetate, are usually volatile fragrant liquids; fats are solid esters 0
noun ester an organic compound, comparable to an inorganic salt: generally, HR (inorganic acid) +R1OH (alcohol) = RR1 (ester) + H2O (water) or RCOOH (organic acid) + R1OH = RCOOR1 (ester) + H2O 0
