mercaptopurine
/məːˌkaptə(ʊ)ˈp(j)ʊəriːn/ /məːˈkaptə(ʊ)ˈpjɔːriːn/Chiefly Medicine
noun
Any of various thiol derivatives of purine; specifically 6-mercaptopurine, C5H4N4S, an antineoplastic agent given orally in the treatment of leukaemia.
Origin
1950s; earliest use found in American Journal of the Medical Sciences. From mercapto- + purine.