glycosaminoglycan

https://doi.org/10.1351/goldbook.G02659
The carbohydrate units in proteoglycans are polysaccharides that contain amino sugars; these polysaccharides are known as glycosaminoglycans.
Source:
White Book, 2nd ed., p. 85 (https://www.qmul.ac.uk/sbcs/iupac/bibliog/white.html)