Dictionary
chi•tin
Pronunciation: (kī'tin), [key]—
n. Biochem.
a nitrogen-containing polysaccharide, related chemically to cellulose, that forms a semitransparent horny substance and is a principal constituent of the exoskeleton, or outer covering, of insects, crustaceans, and arachnids.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.