Chemistry. a polymer in which the monomer units are linked together by the group –COO–, usually formed by polymerizing a polyhydric alcohol with a polybasic acid: used chiefly in the manufacture of resins, plastics, and textile fibers.
Also called poly. a fabric made from such textile fibers.
(pŏl'ē-ěs'tər) Any of various mostly synthetic polymers that are light, strong resins resistant to weather and corrosion. Polyesters are long chains of esters and are used to make fibers and plastics. They are thermosetting. Some polyesters, such as suberin, occur naturally.