The Collaborative International Dictionary of English v.0.48:

simvastatin \sim`va*stat"in\, n.
   a chemical substance (C25H38O5) having inhibitory activity
   on the enzyme HMG-CoA reductase, and used in medicine to
   reduce cholesterol levels in blood.

   Syn: synvinolin; MK-733; Zocor.
        [PJC]