Wordnet 3.0
NOUN (1)
1.
a crystalline amino acid found in proteins (especially keratin);
discovered in bladder stones;
The Collaborative International Dictionary of English v.0.48:
Cystine \Cyst"ine\ (s?s"t?n; 104), n. [See Cyst.] (Physiol.
Chem.)
A white crystalline substance, C3H7NSO2, containing
sulphur, occuring as a constituent of certain rare urinary
calculi, and occasionally found as a sediment in urine.
[1913 Webster]
WordNet (r) 3.0 (2006):
cystine
n 1: a crystalline amino acid found in proteins (especially
keratin); discovered in bladder stones