This is the 5679th most frequent Catalan word.
ester
"Ester" in Catalan refers to a chemical compound formed by the reaction between an acid and an alcohol, with the elimination of water.
In this sentence, 'ester' could refer to a proper name, but it depends on the context in use.
L'ester va fer un bon treball a l'escola.
The ester did a good job at school.
Here, 'ester' pertains to the chemical compound, commonly studied in chemistry.
El químic va analitzar les propietats de l'ester en el laboratori.
The chemist analyzed the properties of the ester in the laboratory.
This usage of 'ester' again refers to the chemical substance, relevant to industrial or chemical processes.