polyesterPronunciation: /ˌpɒlɪˈɛstə/Translate polyester | into German | into Italian | into Spanish Definition of polyester noun [mass noun] a synthetic resin in which the polymer units are linked by ester groups, used chiefly to make synthetic textile fibres. a fabric made from polyester fibre: swimwear in a range of fabrics including polyester and silk [count noun]:dresses in printed polyesterspolyester in other Oxford dictionaries Definition of polyester in the US English dictionary