The Collaborative International Dictionary of English v.0.48:

Physic \Phys"ic\ (f[i^]z"[i^]k), v. t. [imp. & p. p. Physiced
   (f[i^]z"[i^]kt); p. pr. & vb. n. Physicking
   (f[i^]z"[i^]k*[i^]ng).]
   1. To treat with physic or medicine; to administer medicine
      to, esp. a cathartic; to operate on as a cathartic; to
      purge.
      [1913 Webster]

   2. To work on as a remedy; to heal; to cure.
      [1913 Webster]

            The labor we delight in physics pain. --Shak.
      [1913 Webster]

            A mind diseased no remedy can physic. --Byron.
      [1913 Webster]

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      superseded by medicine.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
    n 1: a purging medicine; stimulates evacuation of the bowels
         [syn: purgative, cathartic, physic, aperient]

Moby Thesaurus II by Grady Ward, 1.0:

110 Moby Thesaurus words for "physic":
   Medicaid, Medicare, Newtonian physics, acoustics, aerophysics,
   aerospace medicine, aperient, applied physics, astrophysics, balm,
   balsam, basic conductor physics, biomedicine, biophysics,
   carminative, cathartic, chemical physics, clinical medicine,
   comparative medicine, constitutional medicine, cryogenics,
   crystallography, cure, cytophysics, diuretic, dosimetric medicine,
   drops, drug, electron physics, electronics, electrophysics,
   electuary, elixir, ethical drug, experimental medicine,
   generic name, geophysics, herbs, inhalant, internal medicine,
   laxative, leechcraft, leechdom, legal medicine, lincture, linctus,
   macrophysics, materia medica, mathematical physics, mechanics,
   medical jurisprudence, medicament, medication, medicinal,
   medicinal herbs, medicine, medicophysics, microphysics,
   military medicine, mixture, natural philosophy, natural science,
   naval medicine, neo-Hippocratic medicine, nonprescription drug,
   nuclear physics, officinal, optics, patent medicine, pharmacon,
   philosophy, physical chemistry, physical medicine,
   physical science, physicochemistry, physicomathematics, physics,
   powder, preclinical medicine, preparation, prescription drug,
   preventive medicine, proprietary, proprietary medicine,
   proprietary name, psychophysics, psychosomatic medicine,
   public health medicine, purgative, purge, radiation physics,
   radionics, simples, socialized medicine, solar physics,
   solid-state physics, space medicine, state medicine, statics,
   stereophysics, syrup, theoretical physics, theraputant, therapy,
   thermodynamics, tisane, tropical medicine, vegetable remedies,
   veterinary medicine, zoophysics