'Cystine' definitions:

Definition of 'cystine'

(from WordNet)
noun
A crystalline amino acid found in proteins (especially keratin); discovered in bladder stones

Definition of 'Cystine'

From: GCIDE
  • 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]