The Collaborative International Dictionary of English v.0.48:

Medicament \Med"i*ca*ment\, n. [L. medicamentum, fr. medicare,
   medicari, to heal: cf. F. m['e]dicament. See Medicable.]
   Anything used for healing diseases or wounds, especially a
   medicine; a medication; a healing application.
   [1913 Webster]

WordNet (r) 3.0 (2006):

medicament
    n 1: (medicine) something that treats or prevents or alleviates
         the symptoms of disease [syn: medicine, medication,
         medicament, medicinal drug]