The Collaborative International Dictionary of English v.0.48:

indomethacin \in`do*meth"a*cin\, n. (Chem., Med.)
   A nonsteroidal anti-inflammatory, antipyretic and analgesic
   substance (C19H16ClNO4) prepared synthetically and used for
   the treatment of pain and arthritis. It blocks prostaglandin
   biosynthesis. Chemically, it is
   1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indole-3-acetic
   acid.
   [PJC]