chitin
chi.tin \'ki-t-*n\ \'ki-t-*n-*s, 'ki-t-n*s\ n [F chitine, fr. LN Chiton, genus of mollusks] : an amorphous horny polysaccharide that forms part of the hard outer inte gument of insects, crustaceans, and some other invertebrates - chi.tin.ous aj