Wiktionary
galactan
n. (context carbohydrate English) A polysaccharide consisting of many galactose residues.
Wikipedia
Galactan
Galactan (galactosan) is a polysaccharide consisting of polymerized galactose.
Galactan derived from Anogeissus latifolia is primarily α(1→6), but galactan from acacia trees is primarily α(1→3).