The Collaborative International Dictionary of English v.0.48:

Physic \Phys"ic\ (f[i^]z"[i^]k), n. [OE. phisike, fisike, OF.
   phisique, F. physique knowledge of nature, physics, L.
   physica, physice, fr. Gr. fysikh`, fr. fysiko`s natural, from
   fy`sis nature, fr. fy`ein to produce, grow, akin to E. be.
   See Be, and cf. Physics, Physique.]
   1. The art of healing diseases; the science of medicine; the
      theory or practice of medicine; -- an archaic term,
      superseded by medicine. [archaic] "A doctor of physik."
      --Chaucer.
      [1913 Webster]

   2. A specific internal application for the cure or relief of
      sickness; a remedy for disease; a medicine.
      [1913 Webster]

   3. Specifically, a medicine that purges; a cathartic.
      [1913 Webster]

   4. A physician. [R.] --Shak.
      [1913 Webster]

   Physic nut (Bot.), a small tropical American euphorbiaceous
      tree (Jatropha Curcas), and its seeds, which are well
      flavored, but contain a drastic oil which renders them
      dangerous if eaten in large quantities.
      [1913 Webster]

WordNet (r) 3.0 (2006):

physic nut
    n 1: small tropical American tree yielding purple dye and a
         tanning extract and bearing physic nuts containing a
         purgative oil that is poisonous in large quantities [syn:
         physic nut, Jatropha curcus]