hyalin Syllabification: (hy·a·lin)Pronunciation: /ˈhīəlin/Definition of hyalin noun Physiology a clear substance produced especially by the degeneration of epithelial or connective tissues. Origin: mid 19th century: via Latin from Greek hualinos, from hualos 'glass'hyalin in other Oxford dictionaries Definition of hyalin in the British & World English dictionary