peptidoglycan Syllabification: (pep·ti·do·gly·can)Pronunciation: /ˌpeptidōˈglīˌkan/Definition of peptidoglycan noun Biochemistry a substance forming the cell walls of many bacteria, consisting of glycosaminoglycan chains interlinked with short peptides. peptidoglycan in other Oxford dictionaries Definition of peptidoglycan in the British & World English dictionary